An activity is something you do, or just the state of doing. You might plan some indoor activities for a rainy day, or you might just rely on watching your gerbils' activity in their cage.

Usually, when you use an article like an or the in front of activity, you are referring to a specific event. For example, you might search for the best activity on the cruise ship to fill your afternoon — shuffleboard, anyone? If you take the article away, and you refer to activity, you are usually referring to action. If there is too much activity on the cruise ship dance floor, you might want to avoid that zone.

Definitions of activity
  1. noun
    any specific behavior
    “they avoided all recreational activity
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    being inactive; being less active
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    variance, variation
    an activity that varies from a norm or standard
    space walk
    any kind of physical activity outside a spacecraft by one of the crew
    domestic activities or life
    the activity of operating something (a machine or business etc.)
    a planned activity involving many people performing various actions
    pattern, practice
    a customary way of operation or behavior
    diversion, recreation
    an activity that diverts or amuses or stimulates
    bag, cup of tea, dish
    an activity that you like or at which you are superior
    follow-up, followup
    an activity that continues something that has already begun or that repeats something that has already been done
    a contest with rules to determine a winner
    play, turn
    (game) the activity of doing something in an agreed succession
    musical activity (singing or whistling etc.)
    acting, performing, playacting, playing
    the performance of a part or role in a drama
    animation, liveliness
    general activity and motion
    burst, fit
    a sudden flurry of activity (often for no obvious reason)
    activity directed toward making or doing something
    deeds, works
    performance of moral or religious acts
    (law) the acts performed by an English feudal tenant for the benefit of his lord which formed the consideration for the property granted to him
    business, job, line, line of work, occupation
    the principal activity in your life that you do to earn money
    any activity that occupies a person's attention
    committal to writing, writing
    the activity of putting something in written form
    normal or customary activity of a person in a particular social setting
    actus reus, misconduct, wrongdoing, wrongful conduct
    activity that transgresses moral or civil law
    dissipation, waste, wastefulness
    useless or profitless activity; using or expending or consuming thoughtlessly or carelessly
    attempt, effort, endeavor, endeavour, try
    earnest and conscientious activity intended to do or accomplish something
    the activity of managing or exerting control over something
    the activity of protecting someone or something
    sensory activity
    activity intended to achieve a particular sensory result
    didactics, education, educational activity, instruction, pedagogy, teaching
    the activities of educating or instructing; activities that impart knowledge or skill
    grooming, preparation, training
    activity leading to skilled behavior
    an activity that stands as an equivalent of something or results in an equivalent
    creation, creative activity
    the human act of creating
    disassembly, dismantlement, dismantling
    the act of taking something apart (as a piece of machinery)
    the act of puncturing or perforating
    hunt, hunting, search
    the activity of looking thoroughly in order to find something or someone
    employment, exercise, usage, use, utilisation, utilization
    the act of using
    military operation, operation
    activity by a military or naval force (as a maneuver or campaign)
    measure, measurement, measuring, mensuration
    the act or process of assigning numbers to phenomena according to a rule
    calibration, standardisation, standardization
    the act of checking or adjusting (by comparison with a standard) the accuracy of a measuring instrument
    organisation, organization
    the activity or result of distributing or disposing persons or things properly or methodically
    the activity of putting things together in groups
    support, supporting
    the act of bearing the weight of or strengthening
    continuance, continuation
    the act of continuing an activity without interruption
    procedure, process
    a particular course of action intended to achieve a result
    any activity that is performed in an especially solemn elaborate or formal way
    the proper or conventional behavior on some solemn occasion
    the activity of worshipping
    activating, activation, energizing
    the activity of causing to have energy and be active
    concealing, concealment, hiding
    the activity of keeping something secret
    emplacement, locating, location, placement, position, positioning
    the act of putting something in a certain place
    provision, supply, supplying
    the activity of supplying or providing something
    the act of demanding
    an activity that affords enjoyment
    delectation, enjoyment
    the act of receiving pleasure from something
    lamentation, mourning
    the passionate and demonstrative activity of expressing grief
    the activity of laughing; the manifestation of joy or mirth or scorn
    market, market place, marketplace
    the world of commercial activity where goods and services are bought and sold
    the activities and affairs involved in managing a state or a government
    preparation, readying
    the activity of putting or setting in order in advance of some act or purpose
    aid, assist, assistance, help
    the activity of contributing to the fulfillment of a need or furtherance of an effort or purpose
    the activity of providing for or maintaining by supplying with money or necessities
    behavior, behaviour, conduct, doings
    manner of acting or controlling yourself
    behavior, behaviour
    (psychology) the aggregate of the responses or reactions or movements made by an organism in any situation
    leadership, leading
    the activity of leading
    precedence, precedency, precession
    the act of preceding in time or order or rank (as in a ceremony)
    any activity that is performed alone without assistance
    a confusion of activity and gossip
    violent and excited activity
    hell, sin
    violent and excited activity
    outlet, release, vent
    activity that frees or expresses creative energy or emotion
    a person's dying act; the final thing a person can do
    mystification, obfuscation
    the activity of obscuring people's understanding, leaving them baffled or bewildered
    the activity or business of negotiating an agreement; coming to terms
    verbalisation, verbalization
    the activity of expressing something in words
    disturbance, perturbation
    activity that is a malfunction, intrusion, or interruption
    the act or process of determining the time
    work of little or no value done merely to look busy
    fire control
    preparation for the delivery of shellfire on a target
    (baseball) the batter's attempt to get on base
    the supreme effort one can make
    the weakest effort or poorest achievement one is capable of
    Bertillon system
    a system or procedure for identifying persons
    the procedure of taking inked impressions of a person's fingerprints for the purpose of identification
    genetic fingerprinting, genetic profiling
    the procedure of analyzing the DNA in samples of a person's body tissue or body fluid for the purpose of identification
    (game) a player's turn to take some action permitted by the rules of the game
    diagnostic procedure, diagnostic technique
    a procedure followed in making a medical diagnosis
    emergency procedure
    (medicine) a procedure adopted to meet an emergency (especially a medical emergency)
    experimental procedure
    the specific techniques used in conducting a particular experiment
    groundbreaking, groundbreaking ceremony
    the ceremonial breaking of the ground to formally begin a construction project
    start, starting
    a turn to be a starter (in a game at the beginning)
    purgation, purification
    a ceremonial cleansing from defilement or uncleanness by the performance of appropriate rites
    lavation, wash, washing
    the work of cleansing (usually with soap and water)
    the act of grouping things or people in pairs
    the use of certain marks to clarify meaning of written material by grouping words grammatically into sentences and clauses and phrases
    rescue operation
    an operation organized to free from danger or confinement
    undercover operation
    an operation involving secret work within a community or institution
    use of biological principles in explaining human especially social behavior
    the practice of cooperating
    the practice (usually by a labor union) of requiring an employer to hire more workers than are required
    the practice of scrupulous adherence to prescribed or external forms
    the practice of keeping one jump ahead of a friend or competitor
    the practice of one person holding more than one benefice at a time
    symbolisation, symbolism, symbolization
    the practice of investing things with symbolic meaning
    practices typical of contemporary life or thought
    occult, occult arts
    supernatural practices and techniques
    the practice of ornamental display
    the practice of eating the flesh of your own kind
    the practice of advancing your career at the expense of your personal integrity
    custom, usage, usance
    accepted or habitual practice
    habitual mode of behavior
    characteristic or habitual practice
    the practice of lobbying; the activities of a lobbyist
    slaveholding, slavery
    the practice of owning slaves
    the practice of making a debtor work for his creditor until the debt is discharged
    unwritten law
    law based on customary behavior
    lynch law
    the practice of punishing people by hanging without due process of law
    the practice of treating (someone or something) badly
    the practice of nonconformity
    the act of repressing; control by holding down
    antic, caper, joke, prank, put-on, trick
    a ludicrous or grotesque act done for fun and amusement
    immersing the body in water or sunshine
    celebration, festivity
    any joyous diversion
    dance, dancing, saltation, terpsichore
    taking a series of rhythmical steps (and movements) in time to music
    amusement, entertainment
    an activity that is diverting and that holds the attention
    escapade, lark
    any carefree episode
    escape, escapism
    an inclination to retreat from unpleasant realities through diversion or fantasy
    eurhythmics, eurhythmy, eurythmics, eurythmy
    the interpretation in harmonious bodily movements of the rhythm of musical compositions; used to teach musical understanding
    fun, merriment, playfulness
    activities that are enjoyable or amusing
    gambling, gaming, play
    the act of playing for stakes in the hope of winning (including the payment of a price for a chance to win a prize)
    an amusement or pastime
    jest, jocularity, joke
    activity characterized by good humor
    night life, nightlife
    the activity of people seeking nighttime diversion (as at the theater, a nightclub, etc.)
    interest, pastime, pursuit
    a diversion that occupies one's time and thoughts (usually pleasantly)
    child's play, play
    activity by children that is guided more by imagination than by fixed rules
    the occupation and skills of a confectioner
    the occupation of athletes who compete for pay
    farming, land
    agriculture considered as an occupation or way of life
    the batting turn of a cricket player or team
    an offensive move in a sport or game
    (American football) a complete play to advance the football
    at-bat, bat
    (baseball) a turn trying to get a hit
    a game played on ice in which heavy stones with handles are slid toward a target
    a game in which balls are rolled at an object or group of objects with the aim of knocking them over or moving them
    a 17th century game; a wooden ball was driven along an alley with a mallet
    athletic game
    a game involving athletic activity
    child's game
    a game enjoyed by children
    card game, cards
    a game played with playing cards
    table game
    a game that is played on a table
    parlor game, parlour game
    a game suitable for playing in a parlor
    gambling game, game of chance
    a game that involves gambling
    zero-sum game
    a game in which the total of all the gains and losses is zero
    caper, frolic, gambol, play, romp
    light-hearted recreational activity for diversion or amusement
    athletics, sport
    an active diversion requiring physical exertion and competition
    bell ringing, carillon, carillon playing
    playing a set of bells that are (usually) hung in a tower
    instrumental music
    music produced by playing a musical instrument
    the production of musical tones (by voice or instrument); especially the exactitude of the pitch relations
    the act of playing a percussion instrument
    vocal music
    music that is vocalized (as contrasted with instrumental music)
    the act of whistling a tune
    characterisation, characterization, enactment, personation, portrayal
    acting the part of a character on stage; dramatically representing the character by speech and action and gesture
    impersonation, personation
    imitating the mannerisms of another person
    method, method acting
    an acting technique introduced by Stanislavsky in which the actor recalls emotions or reactions from his or her own life and uses them to identify with the character being portrayed
    dumb show, mime, pantomime
    a performance using gestures and body movements without words
    business, byplay, stage business
    incidental activity performed by an actor for dramatic effect
    a short theatrical episode
    hamming, overacting
    poor acting by a ham actor
    ostentatious or vainglorious or extravagant or melodramatic conduct
    performing a role in an event that occurred at an earlier time
    acting a particular role (as in psychotherapy)
    fits and starts
    repeated bursts of activity
    the most important or interesting work or activity in a specific area or field
    a damaging piece of work
    the performance of a piece of work
    operation, procedure
    a process or series of acts especially of a practical or mechanical nature involved in a particular form of work
    work done by one person or group that benefits another
    polishing, shining
    the work of making something smooth and shiny by rubbing or waxing it
    land tenure by agricultural service or payment of rent; not burdened with military service
    military service
    land tenure by service in the lord's army
    knight's service
    land tenure by service to the lord as a knight
    heavy lifting
    difficult work
    the work of a housewife
    housekeeping, housework
    the work of cleaning and running a house
    the work of using heat to smooth washed clothes in order to remove any wrinkles
    busywork, make-work
    active work of little value
    the work of cutting down trees for timber
    loose end, unfinished business
    work that is left incomplete
    work to be done at night
    work that involves handling papers: forms or letters or reports etc.
    social service, welfare work
    an organized activity to improve the condition of disadvantaged people in society
    biz, game
    your occupation or line of work
    calling, career, vocation
    the particular occupation for which you are trained
    employment, work
    the occupation for which you are paid
    the job to which you are (or hope to be) appointed
    berth, billet, office, place, position, post, situation, spot
    a job in an organization
    the measurement of tremors and shocks and undulatory movements of earthquakes
    salt mine, treadmill
    a job involving drudgery and confinement
    craft, trade
    the skilled practice of a practical occupation
    an occupation requiring special education (especially in the liberal arts or sciences)
    medium, metier
    an occupation for which you are especially well suited
    coding, cryptography, secret writing, steganography
    act of writing in code or cipher
    the activity of writing by hand
    the activity of inscribing (especially carving or engraving) letters or words
    the activity of representing something by a special system of marks or characters
    accountancy, accounting
    the occupation of maintaining and auditing records and preparing financial reports for a business
    the occupation of taking and printing photographs or making movies
    labor, labour, toil
    productive work (especially physical work done for wages)
    subbing, substituting
    working as a substitute for someone who is ill or on leave of absence
    calisthenics, callisthenics
    the practice of calisthenic exercises
    the exercise of a profession
    investigating, investigation
    the work of inquiring into something thoroughly and systematically
    quantitative analysis, quantitative chemical analysis
    chemical analysis to determine the amounts of each element in the substance
    aid, attention, care, tending
    the work of providing treatment for or attending to someone or something
    work that you are obliged to perform for moral or legal reasons
    gender role
    the overt expression of attitudes that indicate to others the degree of your maleness or femaleness
    (in team sports) the role assigned to an individual player
    mission, missionary work
    the organized work of a religious missionary
    brutalisation, brutalization
    the activity of treating someone savagely or viciously
    encroachment, intrusion, trespass, usurpation, violation
    entry to another's property without right or permission
    civil wrong, tort
    (law) any wrongdoing for which an action for damages may be brought
    misconduct in public office
    misbehavior, misbehaviour, misdeed
    improper or wicked or immoral behavior
    willful negligence
    wrongful conduct by a public official
    doing a proper act in a wrongful or injurious manner
    a wrongful act that the actor had no right to do; improper professional conduct
    professional wrongdoing that results in injury or damage
    the action of perverting something (turning it to a wrong use)
    waste of effort, waste of energy
    a useless effort
    waste of material
    a useless consumption of material
    waste of money
    money spent for inadequate return
    waste of time
    the devotion of time to a useless activity
    extravagance, high life, highlife, lavishness, prodigality
    excessive spending
    spending resources lavishly and wastefully
    wrongdoing that violates another's rights and is unjustly inflicted
    an act that causes someone or something to receive physical damage
    iniquity, injustice, shabbiness, unfairness
    an unjust act
    an act causing pain or damage
    evildoing, transgression
    the act of transgressing; the violation of a law or a duty or moral principle
    erotica, porn, porno, pornography, smut
    creative activity (writing or pictures or films etc.) of no literary or artistic value other than to stimulate sexual desire
    dishonesty, knavery
    lack of honesty; acts of lying or cheating or stealing
    falsification, misrepresentation
    a willful perversion of facts
    an unethical agreement between an attorney and client that the attorney would sue and pay the costs of the client's suit in return for a portion of the damages awarded
    criminal maintenance, maintenance
    the unauthorized interference in a legal action by a person having no interest in it (as by helping one party with money or otherwise to continue the action) so as to obstruct justice or promote unnecessary litigation or unsettle the peace of the community
    infringement, violation
    an act that disregards an agreement or a right
    bid, play
    an attempt to get something
    crack, fling, go, offer, pass, whirl
    a usually brief attempt
    a tentative attempt
    an initial attempt (especially outside your usual areas of competence)
    contribution, part, share
    the part played by a person in bringing about a result
    the attempt to achieve equal rights or status
    mug's game
    a futile or unprofitable endeavor
    power play, squeeze, squeeze play
    an aggressive attempt to compel acquiescence by the concentration or manipulation of power
    an attempt to acquire or gain something
    shot, stab
    informal words for any attempt or effort
    an attempt to score in a game
    nisus, pains, strain, striving
    an effortful attempt to attain a goal
    battle, struggle
    an energetic attempt to achieve something
    takeover attempt
    an attempt to take control of a corporation
    run, test, trial
    the act of testing something
    test, trial
    the act of undergoing testing
    dull or routine preliminary work preparing for an undertaking
    work paid for at a rate per unit of time
    labor, project, task, undertaking
    any piece of work that is undertaken or attempted
    the act of helping or improving yourself without relying on anyone else
    crowd control
    activity of controlling a crowd
    damage control
    an effort to minimize or curtail damage or loss
    federalisation, federalization
    the act of being put under federal control
    flight control
    control from ground stations of airplanes in flight by means of messages transmitted to the pilot electronically
    flood control
    (engineering) the art or technique of trying to control rivers with dams etc in order to minimize the occurrence of floods
    any instance of aggressive extension of authority
    regulating, regulation
    the act of controlling or directing according to rule
    internal control
    an accounting procedure or system designed to promote efficiency or assure the implementation of a policy or safeguard assets or avoid fraud and error etc.
    regularisation, regularization, regulation
    the act of bringing to uniformity; making regular
    ownership, possession
    the act of having and controlling property
    (sport) the act of controlling the ball (or puck)
    power trip
    (slang) a self-aggrandizing action undertaken simply for the pleasure of exercising control over other people
    riot control, riot control operation
    the measures taken to control a riot
    grasping, prehension, seizing, taking hold
    the act of gripping something firmly with the hands (or the tentacles)
    steerage, steering
    the act of steering a ship
    direction, guidance, steering
    the act of setting and holding a course
    air cover
    the use of military aircraft to provide protection against attack by enemy aircraft during ground or naval operations
    the act of shielding from harm
    preservation, saving
    the activity of protecting something from loss or danger
    momism, overprotection, overshielding
    excessive protection
    defence, defense
    the act of defending someone or something against attack or injury
    defence, defense
    protection from harm
    inoculating, vaccinating
    the act of protecting against disease by introducing a vaccine into the body to induce immunity
    the activity of going around or through an area at regular intervals for security purposes
    self-defence, self-defense, self-protection
    the act of defending yourself
    the act of protecting something by surrounding it with material that reduces or prevents the transmission of sound or heat or electricity
    locking, lockup
    the act of locking something up to protect it
    accompaniment, escort
    the act of accompanying someone or something in order to protect them
    the act of protecting something by covering it
    immunisation, immunization
    the act of making immune (especially by inoculation)
    care, charge, guardianship, tutelage
    attention and management implying responsibility for safety
    ruggedisation, ruggedization
    the act of making a piece of equipment rugged (strengthening to resist wear or abuse)
    sealing, waterproofing
    the act of treating something to make it repel water
    calculation, computation, computing
    the procedure of calculating; determining something by mathematical or logical methods
    perception, sensing
    becoming aware of something via the senses
    the teaching of different genders in the same institutions
    continuing education
    a program of instruction designed primarily for adult students who participate part-time
    class, course, course of instruction, course of study
    education imparted in a series of lessons or meetings
    work assigned to and done by a student during a course of study; usually it is evaluated as part of the student's grade in the course
    elementary education
    education in elementary subjects (reading and writing and arithmetic) provided to young students at a grade school
    extension, extension service, university extension
    an educational opportunity provided by colleges and universities to people who are not enrolled as regular students
    extracurricular activity
    educational activities not falling within the scope of the regular curriculum
    higher education
    education provided by a college or university
    secondary education
    education beyond the elementary grades; provided by a high school or college preparatory school
    team teaching
    a method of coordinated classroom teaching involving a team of teachers working together with a single group of students
    work-study program
    an educational plan in which students alternate between paid employment and formal study
    athletic training
    the course of practice and exercise and diet undertaken by an athlete
    training to improve strength or self-control
    (military) the training of soldiers to march (as in ceremonial parades) or to perform the manual of arms
    drill, exercise, practice, practice session, recitation
    systematic training by multiple repetitions
    military training
    training soldiers in military procedures
    training for a new occupation
    the training of an animal (especially the training of a horse for dressage)
    skull practice, skull session
    teaching strategy to an athletic team
    toilet training
    training a young child to use the toilet
    model, modeling, modelling
    the act of representing something (usually on a smaller scale)
    dramatisation, dramatization
    a dramatic representation
    pageant, pageantry
    an elaborate representation of scenes from history, etc.; usually involves a parade with rich costumes
    representing figuratively as by emblem or allegory
    diagramming, schematisation, schematization
    providing a chart or outline of a system
    pictorial representation, picturing
    visual representation as by photography or painting
    the act of representing by a type or symbol; the action of typifying
    the act of creating again
    creating from raw materials
    the act of creating something that is different from the materials that went into it
    the creation of value or wealth by producing goods and services
    the placing of seeds in damp sand or sawdust or peat moss in order to preserve them or promote germination
    creating by mental acts
    the act of creating something by thinking
    art, artistic creation, artistic production
    the creation of beautiful or significant things
    creating by removal
    the act of creating by removing something
    (surgery) the act of puncturing a body cavity or organ with a hollow needle in order to draw out fluid
    the act of punching a hole (especially a row of holes as for ease of separation)
    prick, pricking
    the act of puncturing with a small point
    (medicine) puncture of a vein through the skin in order to withdraw blood for analysis or to start an intravenous drip or to inject medication or a radiopaque dye
    a careful systematic search
    forage, foraging
    the act of searching for food and provisions
    frisk, frisking
    the act of searching someone for concealed weapons or illegal drugs
    looking, looking for
    the act of searching visually
    an organized search (by police) for a person (charged with a crime)
    quest, seeking
    the act of searching for something
    ransacking, rummage
    a thorough search for something (often causing disorder or confusion)
    utilization or exercise
    abuse, misuse
    improper or excessive use
    development, exploitation
    the act of making some area of land or water more profitable or productive or useful
    the act of processing used or abandoned materials for use in creating new products
    application, practical application
    the act of bringing something to bear; using it for a particular purpose
    combined operation
    a military operation carried out cooperatively by two or more allied nations or a military operation carried out by coordination of sea, land, and air forces
    maneuver, manoeuvre, simulated military operation
    a military training exercise
    civil defense
    activities organized by civilians for their own protection in time of war or disaster
    campaign, military campaign
    several related operations aimed at achieving a particular goal (usually within geographical and temporal constraints)
    naval campaign
    an operation conducted primarily by naval forces in order to gain or extend or maintain control of the sea
    military mission, mission
    an operation that is assigned by a higher headquarters
    reenforcement, reinforcement, support
    a military operation (often involving new supplies of men and materiel) to strengthen a military force or aid in the performance of its mission
    attack, onrush, onset, onslaught
    (military) an offensive against an enemy (using weapons)
    offence, offense, offensive
    the action of attacking an enemy
    peacekeeping, peacekeeping mission, peacekeeping operation
    the activity of keeping the peace by military forces (especially when international military forces enforce a truce between hostile groups or nations)
    amphibious operation
    a military operation by both land and sea forces
    information gathering
    the act of collecting information
    psychological operation, psyop
    military actions designed to influence the perceptions and attitudes of individuals, groups, and foreign governments
    covert operation
    an intelligence operation so planned as to permit plausible denial by the sponsor
    moving over territory to search for something
    a very thorough search of a person or a place
    measuring the intensity of electromagnetic radiation (especially of the sun's rays)
    measuring sensitivity to pain or pressure
    recording anemometrical measurements
    measuring wind speed and direction
    the precise measurement of angles
    measurement and study of the human body and its parts and capacities
    arterial blood gases
    measurement of the pH level and the oxygen and carbon dioxide concentrations in arterial blood; important in diagnosis of many respiratory diseases
    measuring sensitivity of hearing
    bathymetry, plumbing
    measuring the depths of the oceans
    (music) calibrating something (an instrument or electronic circuit) to a standard frequency
    adjustment, readjustment, registration
    the act of adjusting something to match a standard
    measurement of quantities of heat
    measurement of human heads
    measuring the optical density of a substance by shining light on it and measuring its transmission
    measuring the dose of radiation emitted by a radioactive source
    fetometry, foetometry
    measurement of a fetus (especially the diameter of the head)
    gravimetry, hydrometry
    the measurement of specific gravity
    hypsography, hypsometry
    measurement of the elevation of land above sea level
    mental measurement
    a generic term used to cover any application of measurement techniques to the quantification of mental functions
    measuring with a micrometer
    the act of making and recording a measurement
    measurement of the dimensions of the bony birth canal (to determine whether vaginal birth is possible)
    measurement of the properties of light (especially luminous intensity)
    the act of discovering or expressing the quantity of something
    radioactive dating
    measurement of the amount of radioactive material (usually carbon 14) that an object contains; can be used to estimate the age of the object
    meter reading, reading
    the act of measuring with meters or similar instruments
    measurement at regular intervals of the amplitude of a varying waveform (in order to convert it to digital form)
    the act of measuring depth of water (usually with a sounding line)
    sound ranging
    locating a source of sound (as an enemy gun) by measurements of the time the sound arrives at microphones in known positions
    act of measuring or arranging or adjusting according to a scale
    the use of a spirometer to measure vital capacity
    the practice of measuring angles and distances on the ground so that they can be accurately plotted on a map
    randomisation, randomization
    a deliberately haphazard arrangement of observations so as to simulate chance
    rationalisation, rationalization, systematisation, systematization
    systematic organization; the act of organizing something according to a system or a rationale
    order, ordering
    the act of putting things in a sequential arrangement
    itemisation, itemization, listing
    the act of making a list of items
    the grouping of musical phrases in a melodic line
    assortment, categorisation, categorization, classification, compartmentalisation, compartmentalization
    the act of distributing things into classes or categories of the same type
    aggregation, assembling, collecting, collection
    the act of gathering something together
    grouping by class or kind or size
    territorialisation, territorialization
    the act of organizing as a territory
    propping up, shoring, shoring up
    the act of propping up with shores
    dangling, hanging, suspension
    the act of suspending something (hanging it from above so it moves freely)
    lengthening, perpetuation, prolongation, protraction
    the act of prolonging something
    repeating, repetition
    the act of doing or performing again
    perseverance, perseveration, persistence
    the act of persisting or persevering; continuing or repeating behavior
    the act of abiding (enduring without yielding)
    prosecution, pursuance
    the continuance of something begun with a view to its completion
    something that survives
    medical procedure
    a procedure employed by medical or dental practitioners
    chromosome mapping, mapping
    (genetics) the process of locating genes on a chromosome
    operating procedure
    a procedure for operating something or for dealing with a given situation
    the act of becoming stiff
    indirect procedure or action
    rigamarole, rigmarole
    a long and complicated and confusing procedure
    modus operandi, routine
    an unvarying or habitual method or procedure
    chanoyu, tea ceremony
    an ancient ritual for preparing and serving and drinking tea
    a ceremonial purification of the Roman population every five years following the census
    religious ceremony, religious ritual
    a ceremony having religious meaning
    military ceremony
    a military custom performed in observance of some event or anniversary
    apotheosis, deification, exaltation
    the elevation of a person (as to the status of a god)
    ancestor worship
    worship of ancestors
    the practice of quoting from books or plays etc.
    the prescribed procedure for conducting religious ceremonies
    exaggerated emphasis on the importance of rites or ritualistic forms in worship
    naturism, nudism
    going without clothes as a social practice
    the habitual practice of systematization and classification
    cross dressing, transvestism, transvestitism
    the practice of adopting the clothes or the manner or the sexual role of the opposite sex
    prayer, supplication
    the act of communicating with a deity (especially as a petition or in adoration or contrition or thanksgiving)
    idolisation, idolization
    the act of worshiping blindly and to excess
    adoration, latria
    the worship given to God alone
    idol worship, idolatry
    the worship of idols; the worship of images that are not God
    cultism, devotion, idolatry, veneration
    religious zeal; the willingness to serve God
    autolatry, idiolatry, self-worship
    the worship of yourself
    arborolatry, tree-worship
    the worship of trees
    astrolatry, worship of heavenly bodies
    the worship of planets or stars
    the worship of the cosmos
    demonolatry, devil-worship, diabolatry
    the acts or rites of worshiping devils
    fire-worship, pyrolatry
    the worship of fire
    hagiolatry, hierolatry
    the worship of saints
    heliolatry, sun-worship
    the worship of the sun
    animal-worship, zoolatry
    the worship of animals
    the worship of a single god but without claiming that it is the only god
    moon-worship, selenolatry
    the worship of the moon
    the activity of thrilling or markedly exciting some person or group
    animation, invigoration, vivification
    the activity of giving vitality and vigour to something
    the activity of formally presenting something (as a prize or reward)
    camouflage, disguise
    the act of concealing the identity of something by modifying its appearance
    activity that tries to conceal something
    cover, covering, masking, screening
    the act of concealing the existence of something by obstructing the view of it
    a false identity and background (especially one created for an undercover agent)
    concealment that attempts to prevent something scandalous from becoming public
    burial, burying
    concealing something under the ground
    smoke screen, smokescreen
    an action intended to conceal or confuse or obscure
    stealing, stealth
    avoiding detection by moving carefully
    money laundering
    concealing the source of illegally gotten money
    apposition, collocation, juxtaposition
    the act of positioning close together (or side by side)
    interposition, intervention
    the act or fact of interposing one thing between or among others
    the act of orienting
    the act of fixing firmly in place
    the act of planting or setting in the ground
    the act of placing in a new position
    the act of putting something in position
    the placement of one thing on top of another
    the placement of the fingers for playing different notes (or sequences of notes) on a musical instrument
    (geometry) the placement of one object ideally in the position of another one in order to show that the two coincide
    the act of supplying dry land with water by means of ditches, etc.
    alimentation, feeding
    the act of supplying food and nourishment
    fueling, refueling
    the activity of supplying or taking on fuel
    care delivery, health care delivery, healthcare delivery
    the provision of health care
    issuance, issue, issuing
    the act of providing an item for general use or for official purposes (usually in quantity)
    handling an operation that involves providing labor and materials be supplied as needed
    the act of supplying something
    the activity of supplying a stock of something
    the act or process of providing aid or help of any sort
    act of demanding or levying by force or authority
    demand for something as rightful or due
    self-control, self-denial, self-discipline
    the act of denying yourself; controlling your impulses
    traffic control
    control of the flow of traffic in a building or a city
    control (by agreement among producers or by government) of the price of a commodity in interstate commerce
    an activity that affords excessive pleasure and enjoyment
    black market
    an illegal market in which goods or currencies are bought and sold in violation of rationing or controls
    buyer's market, buyers' market, soft market
    a market in which more people want to sell than want to buy
    gray market, grey market
    an unofficial market in which goods are bought and sold at prices lower than the official price set by a regulatory agency
    seller's market, sellers' market
    a market in which more people want to buy than want to sell
    labor market
    the market in which workers compete for jobs and employers compete for workers
    providing food and services
    automatic transmission and measurement of data from remote sources by wire or radio or other means
    the measurement of temperature
    the measurement of changes in weight as a function of changes in temperature used as a technique of chemically analyzing substances
    the measurement of intraocular pressure by determining the amount of force needed to make a slight indentation in the cornea
    viscometry, viscosimetry
    the measurement of viscosity
    the distribution of forces in preparation for battle or work
    preliminary preparation as a basis or foundation
    final preparation and adjustments
    the act of making something ready
    an act of formulating a program for a definite course of action
    turnaround, turnround
    act or process of unloading and loading and servicing a vessel or aircraft for a return trip
    prolusion, tune-up, warm-up
    exercising in preparation for strenuous activity
    the act of controlling by restraining someone or something
    act of assisting or making easier the progress or improvement of something
    hand, helping hand
    physical assistance
    recourse, refuge, resort
    act of turning to for assistance
    with the help of or owing to
    ministration, relief, succor, succour
    assistance in time of difficulty
    the act of giving temporary assistance
    an act of help or assistance
    the act of providing something (lodging or seat or food) to meet a need
    boost, encouragement
    the act of giving hope or support to someone
    assistance, such as that provided to an enemy or to a known criminal
    aiding the cause or policy or interests of
    maintenance, sustainment, sustenance, sustentation, upkeep
    the act of sustaining life by food or providing a means of subsistence
    logistic assistance, logistic support
    assistance between and within military commands
    the behavior of a male animal that defines and defends its territory
    deliberately unfriendly behavior
    conduct characteristic of a bohemian
    dirty pool
    conduct that is unfair or unethical or unsportsmanlike
    dirty tricks
    underhand commercial or political behavior designed to discredit an opponent
    discourtesy, offence, offense, offensive activity
    a lack of politeness; a failure to show regard for others; wounding the feelings or others
    the quality of being easy in behavior or style
    the way of the world, the ways of the world
    the manner in which people typically behave or things typically happen
    the playing of a card to start a trick in bridge
    a position of leadership
    a position of leadership (especially in the phrase `take the lead')
    trend setting
    the initiating or popularizing of a trend or fashion
    ruff, trumping
    (card games) the act of taking a trick with a trump when unable to follow suit
    (card games) in a single round, the sequence of cards played by all the players; the high card is the winner
    condition, experimental condition
    the procedure that is varied in order to estimate a variable's effect by comparison with a control condition
    formula, rule
    (mathematics) a standard procedure for solving a class of mathematical problems
    salaah, salaat, salah, salat
    the second pillar of Islam is prayer; a prescribed liturgy performed five times a day (preferably in a mosque) and oriented toward Mecca
    offering words of homage as an act of worship
    bother, fuss, hassle, trouble
    an angry disturbance
    magnetic storm
    a sudden disturbance of the earth's magnetic field; caused by emission of particles from the sun
    (economics) a market in which there are many buyers but only one seller
    (economics) a market in which goods or services are offered by several sellers but there is only one buyer
    (economics) a market in which control over the supply of a commodity is in the hands of a small number of producers and each one can influence prices and affect competitors
    anachronism, misdating, mistiming
    the act of locating something at a time when it could not have existed or occurred
    a game of chance played with a dreidel during the Jewish festival of Hanukkah
    the use of methods that do not cause long-term harm to the environment or deplete natural resources
    a competition or quizzing game in which contestants are asked about obscure or miscellaneous facts
    a job, especially a temporary job
    type of:
    act, deed, human action, human activity
    something that people do or cause to happen
  2. noun
    an organic process that takes place in the body
    “respiratory activity
    synonyms: bodily function, bodily process, body process
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    (physiology) regulation or maintenance of a function or action or reflex etc
    breathing, external respiration, respiration, ventilation
    the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation
    a single complete act of breathing in and out
    the process of taking in and expelling air during breathing
    consumption, ingestion, intake, uptake
    the process of taking food into the body through the mouth (as by eating)
    sex, sex activity, sexual activity, sexual practice
    activities associated with sexual intercourse
    the introduction of semen into the genital tract of a female
    the suspension of consciousness and decrease in metabolic rate
    reaction, response
    a bodily process occurring due to the effect of some antecedent stimulus or agent
    crying, tears, weeping
    the process of shedding tears (usually accompanied by sobs or other inarticulate sounds)
    the cessation of lactation
    muscular action of the alimentary tract in a direction opposite to peristalsis
    discharge, emission, expelling
    any of several bodily processes by which substances go out of the body
    the process of coughing up and spitting out
    festering, maturation, suppuration
    (medicine) the formation of morbific matter in an abscess or a vesicle and the discharge of pus
    the natural process by which the body repairs itself
    the accumulation of blood in an organ
    lachrymation, lacrimation, tearing, watering
    shedding tears
    the production and secretion of milk by the mammary glands
    opsonisation, opsonization
    process whereby opsonins make an invading microorganism more susceptible to phagocytosis
    excessive activity
    peristalsis, vermiculation
    the process of wavelike muscle contractions of the alimentary tract that moves food along
    diaphoresis, hidrosis, perspiration, sudation, sweating
    the process of the sweat glands of the skin secreting a salty fluid
    process in which phagocytes engulf and digest microorganisms and cellular debris; an important defense against infection
    process by which certain cells can engulf and incorporate droplets of fluid
    the formation of the placenta in the uterus
    falling out of hair
    process in which skin pigmentation darkens as a result of exposure to ultraviolet light
    the process of giving off or exhaling water vapor through the skin or mucous membranes
    noctambulation, noctambulism, sleepwalking, somnambulation, somnambulism
    walking by a person who is asleep
    sleep talking, somniloquism, somniloquy
    uttering speech while asleep
    motor control
    control of muscles
    artificial respiration
    an emergency procedure whereby breathing is maintained artificially
    abdominal breathing
    breathing in which most of the respiratory effort is done by the abdominal muscles
    eupnea, eupnoea
    normal relaxed breathing
    energetic (deep and rapid) respiration that occurs normally after exercise or abnormally with fever or various disorders
    slow or shallow breathing
    an increased depth and rate of breathing greater than demanded by the body needs; can cause dizziness and tingling of the fingers and toes and chest pain if continued
    heaving, panting
    breathing heavily (as after exertion)
    Cheyne-Stokes respiration, periodic breathing
    abnormal respiration in which periods of shallow and deep breathing alternate
    smoke, smoking
    the act of smoking tobacco or other substances
    breathing out, exhalation, expiration
    the act of expelling air from the lungs
    snore, snoring, stertor
    the act of snoring or producing a snoring sound
    sniffle, snivel, snuffle
    the act of breathing heavily through the nose (as when the nose is congested)
    breathing with a husky or whistling sound
    second wind
    the return of relatively easy breathing after initial exhaustion during continuous exertion
    aspiration, breathing in, inhalation, inspiration, intake
    the act of inhaling; the drawing in of air (or other gases) as in breathing
    eating, feeding
    the act of consuming food
    deglutition, drink, swallow
    the act of swallowing
    suck, sucking, suction
    the act of sucking
    drinking, imbibing, imbibition
    the act of consuming liquids
    safe sex
    sexual activity (especially sexual intercourse) with the use of measures (such as latex condoms) to avoid the transmission of disease (especially AIDS)
    the act of becoming pregnant; fertilization of an ovum by a spermatozoon
    AI, artificial insemination
    the introduction of semen into the oviduct or uterus by some means other than sexual intercourse
    love, love life, lovemaking, making love, sexual love
    sexual activities (often including sexual intercourse) between two people
    carnal abuse
    any lascivious contact by an adult with the sexual organs of a child (especially not involving sexual intercourse)
    conjugation, coupling, mating, pairing, sexual union, union
    the act of pairing a male and female for reproductive purposes
    breeding, facts of life, procreation, reproduction
    the sexual activity of conceiving and bearing offspring
    arousal, stimulation
    mutual sexual fondling prior to sexual intercourse
    perversion, sexual perversion
    an aberrant sexual practice;
    autoeroticism, autoerotism
    using you own body as a sexual object
    promiscuity, promiscuousness, sleeping around
    indulging in promiscuous (casual and indiscriminate) sexual relations
    unrestrained indulgence in sexual activity
    gayness, homoeroticism, homosexualism, homosexuality, queerness
    a sexual attraction to (or sexual relations with) persons of the same sex
    an orientation of romantic or sexual attraction to more than one gender
    heterosexualism, heterosexuality, straightness
    a sexual attraction to (or sexual relations with) persons of the opposite sex
    bestiality, zooerastia, zooerasty
    sexual activity between a person and an animal
    cat sleep, catnap, forty winks, nap, short sleep, snooze
    sleeping for a short period of time (usually not in bed)
    doze, drowse
    a light fitful sleep
    any reaction that occurs automatically without conscious thought or reflection (especially the undirected behavior seen in psychomotor epilepsy)
    a reaction to a crisis or setback or frustration
    an excessive reaction; a reaction with inappropriate emotional behavior
    Fere phenomenon, GSR, Tarchanoff phenomenon, electrical skin response, electrodermal response, galvanic skin response, psychogalvanic response
    a change in the electrical properties of the skin in response to stress or anxiety; can be measured either by recording the electrical resistance of the skin or by recording weak currents generated by the body
    immune reaction, immune response, immunologic response
    a bodily defense reaction that recognizes an invading substance (an antigen: such as a virus or fungus or bacteria or transplanted organ) and produces antibodies specific against that antigen
    an involuntary orienting response; positive or negative reaction to a stimulus source
    a locomotor response toward or away from an external stimulus by a motile (and usually simple) organism
    a movement that is a response to a stimulus but is not oriented with respect to the source of stimulation
    double take
    a delayed reaction indicating surprise
    inborn reflex, innate reflex, instinctive reflex, physiological reaction, reflex, reflex action, reflex response, unconditioned reflex
    an automatic instinctive unlearned reaction to a stimulus
    learned reaction, learned response
    a reaction that has been acquired by learning
    passage, passing
    a bodily reaction of changing from one place or stage to another
    snivel, sniveling
    whining in a tearful manner
    sob, sobbing
    convulsive gasp made while weeping
    bawling, wailing
    loud cries made while weeping
    a nonverbal reaction
    transfusion reaction
    reaction of the body to a transfusion of blood that is not compatible with its own blood; an adverse reaction can range from fever and hives to renal failure and shock and death
    convalescence, recovery, recuperation
    gradual healing (through rest) after sickness or injury
    elimination, evacuation, excreting, excretion, voiding
    the bodily process of discharging waste matter
    hyperhidrosis, hyperidrosis, polyhidrosis
    excessive and profuse perspiration
    catamenia, flow, menses, menstruation, menstruum, period
    the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause
    conglutination, union
    healing process involving the growing together of the edges of a wound or the growing together of broken bones
    type of:
    biological process, organic process
    a process occurring in living organisms
  3. noun
    the trait of being active; moving or acting rapidly and energetically
    “the level of activity declines with age”
    synonyms: activeness
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    inactiveness, inactivity, inertia
    a disposition to remain inactive or inert
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    animation, brio, invigoration, spiritedness, vivification
    quality of being active or spirited or alive and vigorous
    dynamism, oomph, pizzaz, pizzazz, zing
    the activeness of an energetic personality
    cheerful and lively
    life, liveliness, spirit, sprightliness
    animation and energy in action or expression
    type of:
    a distinguishing feature of your personal nature
  4. noun
    the state of being active
    “his sphere of activity
    synonyms: action, activeness
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    inaction, inactiveness, inactivity
    the state of being inactive
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    the state of being in action or exerting power
    busyness, hum
    the state of being or appearing to be actively engaged in an activity
    behavior, behaviour
    the action or reaction of something (as a machine or substance) under specified circumstances
    eructation, eruption, extravasation
    (of volcanos) pouring out fumes or lava (or a deposit so formed)
    the state of being in effect or being operative
    the state of high or excessive activity or productivity or concentration
    a state in which action is feasible
    a state of steady vigorous action that is characteristic of an activity
    an agency that escapes control and destroys its creator
    the state of being in good working order and ready for operation
    the state of being in operation
    the state of an engine or other mechanism that is idling
    type of:
    the way something is with respect to its main attributes
  5. noun
    a process existing in or produced by nature (rather than by the intent of human beings)
    “volcanic activity
    synonyms: action, natural action, natural process
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    the spread of a group of organisms into new habitats
    (physics) the process in which incident radiated energy is retained without reflection or transmission on passing through a medium
    the process of becoming acid or being converted into an acid
    adiabatic process
    (thermodynamics) any process that occurs without gain or loss of heat
    the process of exposing to air (so as to purify)
    the process of preventing redeposition
    any process in which an atomic or nuclear system acquires an additional particle
    a process whereby a star or planet holds an object in its gravitational field
    the process of separating substances of different densities by the use of a centrifuge
    chemical action, chemical change, chemical process
    (chemistry) any process determined by the atomic and molecular composition and structure of the substances involved
    a process used for separating mixtures by virtue of differences in absorbency
    the formation of stonelike objects within a body organ (e.g., the kidneys)
    the process of changing from a gaseous to a liquid or solid state
    (meteorology) the vertical movement of heat or other properties by massive motion within the atmosphere
    clotting, coagulation, curdling
    the process of forming semisolid lumps in a liquid
    the process of gradually becoming inferior
    demagnetisation, demagnetization
    the process of removing magnetization
    changing from an adsorbed state on a surface to a gaseous or liquid state
    (physics) the process in which there is movement of a substance from an area of high concentration of that substance to an area of lower concentration
    disintegration, dissolution
    separation into component parts
    distillation, distillment
    the process of purifying a liquid by boiling it and condensing its vapors
    the gradual departure from an intended course due to external influences (as a ship or plane)
    the process of bubbling as gas escapes
    cataphoresis, dielectrolysis, electrophoresis, ionophoresis
    the motion of charged particles in a colloid under the influence of an electric field; particles with a positive charge go to the cathode and negative to the anode
    ecesis, establishment
    (ecology) the process by which a plant or animal becomes established in a new habitat
    the reduction of the intensity of radiation as a consequence of absorption and radiation
    the process of obtaining something from a mixture or compound by chemical or physical or mechanical means
    the process in which part of the output of a system is returned to its input in order to regulate its further output
    the process whereby fluids pass through a filter or a filtering medium
    the process of flocculating; forming woolly cloudlike aggregations
    any uninterrupted stream or discharge
    natural process that causes something to form
    fossilisation, fossilization
    the process of fossilizing a plant or animal that existed in some earlier age; the process of being turned to stone
    geologic process, geological process
    (geology) a natural process whereby geological features are modified
    curing, hardening, set, solidification, solidifying
    the process of becoming hard or solid by cooling or drying or crystallization
    the process of rendering inactive
    ion exchange
    a process in which ions are exchanged between a solution and an insoluble (usually resinous) solid; widely used in industrial processing
    ionisation, ionization
    the process of ionizing; the formation of ions by separating atoms or molecules or radicals or by adding or subtracting electrons from atoms by strong electric fields in a gas
    leach, leaching
    the process of leaching
    magnetic induction, magnetisation, magnetization
    the process that makes a substance magnetic (temporarily or permanently)
    materialisation, materialization
    the process of coming into being; becoming reality
    nuclear reaction
    (physics) a process that alters the energy or structure or composition of atomic nuclei
    the process of becoming cloudy or opaque
    the process of oscillating between states
    the process of providing or combining or treating with oxygen
    pair creation, pair formation, pair production
    the transformation of a gamma-ray photon into an electron and a positron when the photon passes close to an atomic nucleus
    phase change, phase transition, physical change, state change
    a change from one state (solid or liquid or gas) to another without a change in chemical composition
    precession of the equinoxes
    a slow westward shift of the equinoxes along the plane of the ecliptic caused by precession of the Earth's axis of rotation
    a process that liberates or discharges something
    (geology) the leaping movement of sand or soil particles as they are transported in a fluid medium over an uneven surface
    the physical process in which particles are deflected haphazardly as a result of collisions
    raising silkworms in order to obtain raw silk
    (technology) a process that acts to absorb or remove energy or a substance from a system
    soak, soakage, soaking
    the process of becoming softened and saturated as a consequence of being immersed in water (or other liquid)
    the process of becoming softer
    the process in which one substance takes up or holds another (by either absorption or adsorption)
    (technology) a process by which energy or a substance enters a system
    rigidification, rigidifying, stiffening
    the process of becoming stiff or rigid
    (physiology) the effect of a stimulus (on nerves or organs etc.)
    ecological succession, succession
    (ecology) the gradual and orderly process of change in an ecosystem brought about by the progressive replacement of one community by another until a stable climax is established
    natural selection, selection, survival, survival of the fittest
    a natural process resulting in the evolution of organisms best adapted to the environment
    synergism, synergy
    the working together of two things (muscles or drugs for example) to produce an effect greater than the sum of their individual effects
    temperature change
    a process whereby the degree of hotness of a body (or medium) changes
    the process whereby a transducer accepts energy in one form and gives back related energy in a different form
    the passage of gases through fine tubes because of differences in pressure or temperature
    the process of becoming vitreous
    heat sink
    a metal conductor specially designed to conduct (and radiate) heat
    adaptive radiation
    the development of many different forms from an originally homogeneous group of organisms as they fill different ecological niches
    airstream, backwash, race, slipstream, wash
    the flow of air that is driven backwards by an aircraft propeller
    turbulent flow
    flow in which the velocity at any point varies erratically
    streamline flow
    flow of a gas or liquid in which the velocity at any point is relatively steady
    absorption, soaking up
    (chemistry) a process in which one substance permeates another; a fluid permeates or is dissolved by a liquid or solid
    stimulation of activity in an organism or chemical
    the process of introducing an acyl group into a compound
    adsorption, surface assimilation
    the accumulation of molecules of a gas to form a thin film on the surface of a solid
    (meteorology) the horizontal transfer of heat or other atmospheric properties
    agglutinating activity, agglutination
    the coalescing of small particles that are suspended in solution; these larger masses are then (usually) precipitated
    gradual formation of new land, by recession of the sea or deposit of sediment
    conversion of starch to sugar
    (chemistry) any process of combination (especially in solution) that depends on relatively weak chemical bonding
    blood clotting, blood coagulation
    a process in which liquid blood is changed into a semisolid mass (a blood clot)
    blueing, bluing
    a process that makes something blue (or bluish)
    a process that impregnates something with calcium (or calcium salts)
    catalysis, contact action
    acceleration of a chemical reaction induced the presence of material that is chemically unchanged at the end of the reaction
    caries, cavity, dental caries, tooth decay
    soft decayed area in a tooth; progressive decay can lead to the death of a tooth
    chain reaction
    a self-sustaining nuclear reaction; a series of nuclear fissions in which neutrons released by splitting one atom leads to the splitting of others
    the process of forming a ring by forming one or more hydrogen bonds
    chemical reaction, reaction
    (chemistry) a process in which one or more substances are changed into others
    the addition or substitution of chlorine in organic compounds
    the breaking of a chemical bond in a molecule resulting in smaller molecules
    climate change, global climate change
    a change in the world's climate
    column chromatography
    chromatography that uses selective adsorption by a column of powders
    congealment, congelation
    the process of congealing; solidification by (or as if by) freezing
    the transfer of heat through a fluid (liquid or gas) caused by molecular motion
    chilling, cooling, temperature reduction
    the process of becoming cooler; a falling temperature
    corroding, corrosion, erosion
    erosion by chemical action
    decay of matter (as by rot or oxidation)
    the process whereby heavy molecules of naphtha or petroleum are broken down into hydrocarbons of lower molecular weight (especially in the oil-refining process)
    deamination, deaminization
    removal of the amino radical from an amino acid or other amino compound
    loss of calcium from bones or teeth
    the process of removing a carboxyl group from a chemical compound (usually replacing it with hydrogen)
    decay, disintegration, radioactive decay
    the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation
    (pharmacology) the extraction of water-soluble drug substances by boiling
    decomposition, putrefaction, rot, rotting
    (biology) the process of decay caused by bacterial or fungal action
    the process of making a (steel) ship's hull nonmagnetic by producing an opposing magnetic field
    dehydration, desiccation, drying up, evaporation
    the process of extracting moisture
    the removal of iodine atoms from organic compounds
    demineralisation, demineralization
    the removal of minerals and mineral salts from a liquid (especially from water)
    desalination, desalinisation, desalinization
    the removal of salt (especially from sea water)
    the gradual transformation of habitable land into desert; is usually caused by climate change or by destructive use of the land
    the process of deformation that produces continents and ocean basins in the earth's crust
    the process of decomposing organic matter (as in sewage) by bacteria or by chemical action or heat
    dilapidation, ruin
    the process of becoming dilapidated
    (chemistry) the temporary or reversible process in which a molecule or ion is broken down into smaller molecules or ions
    the process of extracting one material from another by washing with a solvent to remove adsorbed material from an adsorbent (as in washing of loaded ion-exchange resins to remove captured ions); used to obtain uranium ions
    the release of electrons from parent atoms
    endoergic reaction
    a nuclear reaction occurring with absorption of energy
    eating away, eroding, erosion, wearing, wearing away
    (geology) the mechanical process of wearing or grinding something down (as by particles washing over it)
    exoergic reaction
    a nuclear reaction accompanied by the evolution of energy
    a normal ongoing process that dissolves fibrin and results in the removal of small blood clots
    flow into something (as a container)
    fission, nuclear fission
    a nuclear reaction in which a massive nucleus splits into smaller nuclei with the simultaneous release of energy
    gradual internal motion or deformation of a solid body (as by heat)
    fold, folding
    a geological process that causes a bend in a stratum of rock
    freeze, freezing
    the withdrawal of heat to change something from a liquid to a solid
    fusion, nuclear fusion, nuclear fusion reaction
    a nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy
    galvanisation, galvanization
    stimulation with a galvanic current
    the process of changing into gas
    the process of interacting with gas
    the process of covering the earth with glaciers or masses of ice
    heating, warming
    the process of becoming warmer; a rising temperature
    a chemical process that adds hydrogen atoms to an unsaturated oil
    electrophoresis to separate antigens and antibodies
    encrustation, incrustation
    the formation of a crust
    inflow, influx
    the process of flowing in
    the process of extracting certain active properties (as a drug from a plant) by steeping or soaking (usually in water)
    the forcing of molten rock into fissures or between strata of an earlier rock formation
    intumescence, intumescency, swelling
    the increase in volume of certain substances when they are heated (often accompanied by release of water)
    a chemical process in which the direction of optical rotation of a substance is reversed from dextrorotatory to levorotary or vice versa
    the substitution or addition of iodine atoms in organic compounds
    (of a ship or plane) sideways drift
    (astronomy) a real or apparent slow oscillation of a moon or satellite
    the conversion of a solid or a gas into a liquid
    (biochemistry) dissolution or destruction of cells such as blood cells or bacteria
    softening due to soaking or steeping
    chemical mechanism, mechanism
    the atomic process that occurs during a chemical reaction
    change in the structure of rock by natural agencies such as pressure or heat or introduction of new chemical substances
    the transduction of sound waves into electrical waves (by a microphone)
    beneficiation, mineral dressing, mineral extraction, mineral processing, ore dressing, ore processing
    crushing and separating ore into valuable substances or waste by any of a variety of techniques
    negative feedback
    feedback in opposite phase with (decreasing) the input
    the chemical process in which a nitro group is added to an organic compound (or substituted for another group in an organic compound)
    the process of mountain formation (especially by the upward displacement of the earth's crust)
    (biology, chemistry) diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal
    effluence, efflux, outflow
    the process of flowing out
    paper chromatography
    chromatography that uses selective adsorption on a strip of paper
    carrier electrophoresis, paper electrophoresis
    electrophoresis carried out on filter paper
    peptisation, peptization
    the process of converting to a sol; bringing to a colloidal solution
    infiltration, percolation
    the slow passage of a liquid through a filtering medium
    permeation, pervasion, suffusion
    the process of permeating or infusing something with a substance
    petrifaction, petrification
    the process of turning some plant material into stone by infiltration with water carrying mineral particles without changing the original shape
    synthesis of compounds with the aid of radiant energy (especially in plants)
    polymerisation, polymerization
    a chemical process that combines several monomers to form a polymer or polymeric compound
    positive feedback, regeneration
    feedback in phase with (augmenting) the input
    (medicine) the synergistic effect of two drugs given simultaneously
    the process of forming a chemical precipitate
    the hydrolysis of proteins into peptides and amino acids by cleavage of their peptide bonds
    pyrochemical process, pyrochemistry
    processes for chemical reactions at high temperatures
    (photography) the formation of a network of cracks or wrinkles in a photographic emulsion
    rigor mortis
    muscular stiffening that begins 2 to 4 hours after death and lasts for about 4 days
    the action of forming a chelate or other stable compound with an ion or atom or molecule so that it is no longer available for reactions
    the source of something's existence or from which it derives or is derived
    (physics) a nuclear reaction in which a bombarded nucleus breaks up into many particles
    spoilage, spoiling
    the process of becoming spoiled
    forming or depositing in layers
    a geological process in which one edge of a crustal plate is forced sideways and downward into the mantle below another plate
    synaeresis, syneresis
    the separation of liquid from a gel that is caused by contraction (as in cheese making)
    the process of producing a chemical compound (usually by the union of simpler chemical compounds)
    melt, melting, thaw, thawing
    the process whereby heat changes something from a solid to a liquid
    congealing tissue by heat (as by electric current)
    the process of transfering an amino group from one compound to another
    the process of transposing an amino group within a chemical compound
    an exchange of molecules (and their kinetic energy and momentum) across the boundary between adjacent layers of a fluid or across cell membranes
    centrifugation at very high speeds
    evaporation, vapor, vaporisation, vaporization, vapour
    the process of becoming a vapor
    ferment, fermentation, fermenting, zymolysis, zymosis
    a process in which an agent causes an organic substance to break down into simpler substances; especially, the anaerobic breakdown of sugar into alcohol
    a method of extracting natural gas or oil from rock by injecting liquid at high pressure
    type of:
    physical process, process
    a sustained phenomenon or one marked by gradual changes through a series of states
  6. noun
    (chemistry) the capacity of a substance to take part in a chemical reaction
    “catalytic activity
    see moresee less
    type of:
    capability, capacity
    the susceptibility of something to a particular treatment
Word Family

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