To bound is to jump or hop — usually as you run. Bound can also mean to go or to plan to go, especially to a certain destination, as in being bound for New York or homeward-bound.

Superman can "leap tall buildings in a single bound," but the word bound is usually about boundaries. When you're playing soccer or football, the ball goes "out of bounds." Someone can also be bound with rope — tied up. Commitments are another kind of tie. When you get married, you're bound to your partner. If you make a promise, you're bound to your word. On a less pleasant note, if you're constipated, you're bound up.

Definitions of bound
  1. adjective
    confined by bonds
    bound and gagged hostages”
    chained, enchained
    bound with chains
    fettered, shackled
    bound by chains fastened around the ankles
    furled, rolled
    rolled up and secured
    bound fast especially having the arms restrained
    confined or restricted with or as if with a rope or chain
    tied, trussed
    bound or secured closely
    tied or bound with wire
    hampered and not free; not able to act at will
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    not restrained or tied down by bonds
    unchained, unfettered, unshackled, untied
    not bound by shackles and chains
    not confined or restricted with a tether
    able to act at will; not hampered; not under compulsion or restraint
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  2. adjective
    secured with a cover or binding; often used as a combining form
    bound volumes”
    “leather- bound volumes”
    having trim or fittings of brass
    enclosed in a case
    (of books) having the back bound in one material and the sides in another
    paperback, paperbacked
    (of books) having a flexible binding
    (of books) having a sturdy and attractive binding
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    not secured within a cover
    being or having leaves that can be easily removed or rearranged
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  3. adjective
    held with another element, substance or material in chemical or physical union
    conjugate, conjugated
    of an organic compound; containing two or more double bonds each separated from the other by a single bond
    conjugate, conjugated
    formed by the union of two compounds
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    unconstrained or not chemically bound in a molecule or not fixed and capable of relatively unrestricted motion
    (of a gas e.g.) released from chemical combination
    not held in chemical or physical combination
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  4. adjective
    covered or wrapped with a bandage
    “an injury bound in fresh gauze”
    synonyms: bandaged
    given medical care or treatment
  5. adjective
    bound by an oath
    “a bound official”
    bound by or stated on oath
  6. adjective
    bound by contract
    synonyms: apprenticed, articled, indentured
    hampered and not free; not able to act at will
  7. adjective
    very likely; almost certain to happen
    having a good chance of being the case or of coming about
  8. adjective
    (usually followed by `to') governed by fate
    bound to happen”
    synonyms: destined
    certain, sure
    certain to occur; destined or inevitable
  9. adjective
    headed or intending to head in a certain direction; often used as a combining form as in `college-bound students'
    “children bound for school”
    synonyms: destined
    orientated, oriented
    adjusted or located in relation to surroundings or circumstances; sometimes used in combination
  10. adjective
    confined in the bowels
    “he is bound in the belly”
    have difficult or incomplete or infrequent evacuation of the bowels
  11. noun
    the line or plane indicating the limit or extent of something
    synonyms: boundary, bounds
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    the boundary in ancient times between Italy and Gaul; Caesar's crossing it with his army in 49 BC was an act of war
    Mohorovicic discontinuity
    the boundary between the Earth's crust and the underlying mantle
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    the natural margin formed by hair on the head
    an international boundary or the area (often fortified) immediately inside the boundary
    the boundary marking the edge of the sun's influence; the boundary (roughly 100 AU from the sun) between the interplanetary medium and the interstellar medium; where the solar wind from the sun and the radiation from other stars meet
    border, borderline, boundary line, delimitation, mete
    a line that indicates a boundary
    bourn, bourne
    an archaic term for a boundary
    district line
    the boundary between two districts
    county line
    the boundary between two counties
    city line
    the boundary of a city
    border, edge
    the boundary of a surface
    a boundary marking the extremities of something
    demarcation, demarcation line, limit
    the boundary of a specific area
    lineation, outline
    the line that appears to bound an object
    the extended two-dimensional outer boundary of a three-dimensional object
    a boundary line between land and water
    the outside limit of an object or area or surface; a place farthest away from the center of something
    (chemistry) a surface forming a common boundary between two things (two objects or liquids or chemical phases)
    hard palate
    the bony part of the roof of the mouth
    palate, roof of the mouth
    the upper surface of the mouth that separates the oral and nasal cavities
    face, side
    a surface forming part of the outside of an object
    circuit, circumference
    the boundary line encompassing an area or object
    fence line
    a boundary line created by a fence
    property line
    the boundary line between two pieces of property
    state boundary, state line
    the boundary between two states
    the edge of a steep place
    celestial sphere, empyrean, firmament, heavens, sphere, vault of heaven, welkin
    the apparent surface of the imaginary sphere on which celestial bodies appear to be projected
    city limit, city limits
    the limits of the area occupied by a city or town
    the surface at either extremity of a three-dimensional object
    inside, interior
    the inner or enclosed surface of something
    (astronomy) the circumferential edge of the apparent disc of the sun or the moon or a planet
    upper limit
    the limit on the upper (or northernmost) side of something
    lower limit
    the limit on the lower (or southernmost) side of something
    the outline of a coast
    an outline of a solid object (as cast by its shadow)
    exterior, outside
    the outer side or surface of something
    the outline of objects seen against the sky
    substrate, substratum
    a surface on which an organism grows or is attached
    three-mile limit
    the limit of a nation's territorial waters
    wave front, wavefront
    (physics) an imaginary surface joining all points in space that are reached at the same instant by a wave propagating through a medium
    the intensely luminous surface of a star (especially the sun)
    type of:
    the outermost or farthest region or point
  12. noun
    a line determining the limits of an area
    synonyms: boundary, edge
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    the shape of a raised edge of a more or less circular object
    border, margin, perimeter
    the boundary line or the area immediately inside the boundary
    fringe, outer boundary, periphery
    the outside boundary or surface of something
    brink, threshold, verge
    a region marking a boundary
    upper bound
    (mathematics) a number equal to or greater than any other number in a given set
    lower bound
    (mathematics) a number equal to or less than any other number in a given set
    the middle of the chief navigable channel of a waterway that forms the boundary line between states
    either the outer margin or the inner margin of the aperture of a gastropod's shell
    type of:
    a length (straight or curved) without breadth or thickness; the trace of a moving point
  13. noun
    the greatest possible degree of something
    “what he did was beyond the bounds of acceptable behavior”
    synonyms: boundary, limit
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    a narrow boundary
    absoluteness, starkness, utterness
    the quality of being complete or utter or extreme
    heat barrier, thermal barrier
    a limit to high speed flight imposed by aerodynamic heating
    level best, maximum, utmost, uttermost
    the greatest possible degree
    brink, cusp, verge
    the limit beyond which something happens or changes
    the brink of a dangerous or potentially disastrous situation
    type of:
    the distance or area or volume over which something extends
  14. verb
    form the boundary of; be contiguous to
    synonyms: border
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    form the edge of
    border on; come close to
    serve as a shore to
    type of:
    confine, enclose, hold in
    close in; "darkness confined him"
  15. verb
    place limits on (extent or access)
    synonyms: confine, limit, restrain, restrict, throttle, trammel
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    reduce, tighten
    narrow or limit
    limit or restrict to
    restrict (school boys') movement to the dormitory or campus as a means of punishment
    draw a line, draw the line
    reasonably object (to) or set a limit (on)
    mark off, mark out
    set boundaries to and delimit
    harness, rein, rule
    keep in check
    baffle, regulate
    check the emission of (sound)
    cramp, halter, hamper, strangle
    prevent the progress or free movement of
    constrain, stiffen, tighten, tighten up
    clamp down, crack down
    repress or suppress (something regarded as undesirable)
    constrict, inhibit
    limit the range or extent of
    constrain, cumber, encumber, restrain
    hold back
    put a bridle on
    keep to the curb
    impede the motion of, as with a chain or a burden
    type of:
    check, contain, control, curb, hold, hold in, moderate
    lessen the intensity of; temper; hold in restraint; hold or keep within limits
  16. verb
    move forward by leaps and bounds
    “The horse bounded across the meadow”
    synonyms: jump, leap, spring
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    jump straight up
    bounce, rebound, recoil, resile, reverberate, ricochet, spring, take a hop
    spring back; spring away from an impact
    move suddenly, energetically, or violently
    leap suddenly
    perform a capriole, of horses in dressage
    move around heavily and clumsily
    ski jump
    jump on skis
    leap or skip, often in dancing
    bound vigorously
    jump across
    overleap, vault
    jump across or leap over (an obstacle)
    perform a leap where both hind legs come off the ground, of a horse
    hop, hop-skip, skip
    jump lightly
    jump about playfully
    make a jump forward or upward
    kick, kick back, recoil
    spring back, as from a forceful thrust
    bound off, skip
    bound off one point after another
    rebound after hitting
    jump a hurdle
    type of:
    move so as to change position, perform a nontranslational motion
  17. verb
    spring back; spring away from an impact
    synonyms: bounce, rebound, recoil, resile, reverberate, ricochet, spring, take a hop
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    kick, kick back, recoil
    spring back, as from a forceful thrust
    bound off, skip
    bound off one point after another
    rebound after hitting
    type of:
    jump, leap, spring
    move forward by leaps and bounds
  18. noun
    a light, self-propelled movement upwards or forwards
    synonyms: bounce, leap, leaping, saltation, spring
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    caper, capriole
    a playful leap or hop
    the act of pouncing
    type of:
    jump, jumping
    the act of jumping; propelling yourself off the ground
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