Anything that has weight and shape has mass. In fact, mass is the quality that gives things weight anywhere there's gravity.

If you think about mass being about weight and shape, you can see how many of its meanings are related. If something is very big we say it has great mass — or is massive. If we talk about a large group of people, we talk about a mass demonstration or a mass of demonstrators. We refer to poor or common people as the masses — there are a lot of them. Doctors refer to tumors inside our bodies as masses.

Definitions of mass
  1. noun
    the property of a body that causes it to have weight in a gravitational field
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    the main mass of a thing
    the total mass of living matter in a given unit area
    critical mass
    the minimum mass of fissionable material that can sustain a chain reaction
    rest mass
    (physics) the mass of a body as measured when the body is at rest relative to an observer, an inherent property of the body
    relativistic mass
    (physics) the mass of a body in motion relative to the observer: it is equal to the rest mass multiplied by a factor that is greater than 1 and that increases as the magnitude of the velocity increases
    the property possessed by a large mass
    gravitational mass
    (physics) the mass of a body as measured by its gravitational attraction for other bodies
    inertial mass
    (physics) the mass of a body as determined by the second law of motion from the acceleration of the body when it is subjected to a force that is not due to gravity
    atomic mass, atomic weight, relative atomic mass
    (chemistry) the mass of an atom of a chemical element expressed in atomic mass units
    mass energy
    (physics) the mass of a body regarded relativistically as energy
    molecular weight, relative molecular mass
    (chemistry) the sum of the relative atomic masses of the constituent atoms of a molecule
    mass defect, mass deficiency
    the amount by which the mass of an atomic nucleus is less than the sum of the masses of its constituent particles
    combining weight, eq, equivalent, equivalent weight
    the atomic weight of an element that has the same combining capacity as a given weight of another element; the standard is 8 for oxygen
    meq, milliequivalent
    one-thousandth of an equivalent
    type of:
    physical property
    any property used to characterize matter and energy and their interactions
    fundamental measure, fundamental quantity
    one of the four quantities that are the basis of systems of measurement
  2. noun
    a body of matter without definite shape
    “a huge ice mass
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    coprolith, faecalith, fecalith, stercolith
    a hard mass of fecal matter
    a large mass of material that is heaped up by the wind or by water currents
    a mass that is densely tangled or interwoven
    mush, pulp
    any soft or soggy mass
    a mound of glacial drift
    a mass of snow heaped up by the wind
    type of:
    an individual 3-dimensional object that has mass and that is distinguishable from other objects
  3. noun
    an ill-structured collection of similar things (objects or people)
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    an immovable mass of logs blocking a river
    a bushy thick mass (especially hair)
    type of:
    accumulation, aggregation, assemblage, collection
    several things grouped together or considered as a whole
  4. noun
    the common people generally
    “separate the warriors from the mass
    synonyms: hoi polloi, masses, multitude, people, the great unwashed
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    laity, temporalty
    in Christianity, members of a religious community that do not have the priestly responsibilities of ordained clergy
    the part of the general public interested in a source of information or entertainment
    followers, following
    a group of followers or enthusiasts
    the audience reached by written communications (books or magazines or newspapers etc.)
    TV audience, viewers, viewing audience
    the audience reached by television
    a group of followers hired to applaud at a performance
    any loyal and steadfast following
    the fans of a sport or famous person
    type of:
    group, grouping
    any number of entities (members) considered as a unit
  5. noun
    the property of something that is great in magnitude
    “he received a mass of correspondence”
    synonyms: bulk, volume
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    dollar volume, turnover
    the volume measured in dollars
    type of:
    the property of relative size or extent (whether large or small)
  6. noun
    (often followed by `of') a large number or amount or extent
    synonyms: batch, deal, flock, good deal, great deal, hatful, heap, lot, mess, mickle, mint, mountain, muckle, passel, peck, pile, plenty, pot, quite a little, raft, sight, slew, spate, stack, tidy sum, wad
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    barrage, deluge, flood, flurry, inundation, torrent
    an overwhelming number or amount
    a mass of hay piled up in a barn for preservation
    type of:
    large indefinite amount, large indefinite quantity
    an indefinite quantity that is above the average in size or magnitude
  7. adjective
    formed of separate units gathered into a mass or whole
    synonyms: aggregate, aggregated, aggregative
    forming a whole or aggregate
  8. verb
    join together into a mass or collect or form a mass
    “Crowds were massing outside the palace”
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    crowd closely
    type of:
    crowd, crowd together
    to gather together in large numbers
  9. noun
    (Roman Catholic Church and Protestant Churches) the celebration of the Eucharist
    synonyms: Mass
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    High Mass
    a solemn and elaborate Mass with music
    Low Mass
    a Mass recited without music
    a Mass celebrated for the dead
    type of:
    religious ceremony, religious ritual
    a ceremony having religious meaning
Word Family

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