Something is double if it has two parts or if there are two versions of it. If you order a double dip ice cream cone, there will be two scoops of ice cream for you to lick.

If you fall while you're roller skating and end up with a double arm fracture, it means you broke your arm in two places. A joke with a double meaning has two of them, and if you double your tips at the coffee shop by smiling more at customers, you're making twice as much money. In addition to the adjective and verb versions of double, there's the noun: your double is someone who looks exactly like you.

Definitions of double
  1. adjective
    consisting of or involving two parts or components usually in pairs
    “an egg with a double yolk”
    “a double (binary) star”
    double doors”
    “duple (or double) time consists of two (or a multiple of two) beats to a measure”
    synonyms: dual, duple
    having or involving or consisting of more than one part or entity or individual
  2. adjective
    having more than one decidedly dissimilar aspects or qualities
    “a double (or dual) role for an actor”
    “"every episode has its double and treble meaning"-Frederick Harrison”
    synonyms: dual, three-fold, threefold, treble, two-fold, twofold
    having or involving or consisting of more than one part or entity or individual
  3. adjective
    having two meanings with intent to deceive
    “a sly double meaning”
    synonyms: forked
    ambiguous, equivocal
    open to two or more interpretations; or of uncertain nature or significance; or (often) intended to mislead
  4. adjective
    twice as great or many
    “ate a double portion”
    “the dose is doubled
    synonyms: doubled, two-fold, twofold
    having or involving or consisting of more than one part or entity or individual
  5. adjective
    large enough for two
    “a double bed”
    “a double room”
    big, large
    above average in size or number or quantity or magnitude or extent
  6. adjective
    used of homologous chromosomes associated in pairs in synapsis
    synonyms: bivalent
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    used of a chromosome that is not paired or united with its homologous chromosome during synapsis
    used of the association of three or more homologous chromosomes during the first division of meiosis
    show more antonyms...
  7. adverb
    two together
    “some people sleep better double
  8. adverb
    to double the degree
    “his eyes were double bright”
    synonyms: doubly, twice
  9. noun
    a quantity that is twice as great as another
    “36 is the double of 18”
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    type of:
    the product of a quantity by an integer
  10. noun
    raising the stakes in a card game by a factor of 2
    “I decided his double was a bluff”
    synonyms: doubling
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    type of:
    increasing the size of a bet (as in poker)
  11. noun
    a base hit on which the batter stops safely at second base
    “he hit a double to deep centerfield”
    synonyms: two-bagger, two-base hit, two-baser
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    line double, line-drive double
    a double resulting from a line drive
    type of:
    base hit, safety
    (baseball) the successful act of striking a baseball in such a way that the batter reaches base safely
  12. verb
    increase twofold
    “The population doubled within 50 years”
    synonyms: duplicate
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    double again
    arrange or combine in pairs
    type of:
    manifold, multiply
    combine or increase by multiplication
  13. verb
    do double duty; serve two purposes or have two functions
    “She doubles as his wife and secretary”
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    type of:
    function, go, operate, run, work
    perform as expected when applied
  14. verb
    hit a two-base hit
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    type of:
    cause to move by striking
  15. verb
    make or do or perform again
    synonyms: duplicate, reduplicate, repeat, replicate
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    copy, replicate
    reproduce or make an exact copy of
    repeat stages of evolutionary development during the embryonic phase of life
    geminate, reduplicate
    form by reduplication
    type of:
    make a copy or equivalent of
  16. noun
    a stand-in for movie stars to perform dangerous stunts
    “his first job in Hollywood was as a double for Clark Gable”
    synonyms: stunt man, stunt woman
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    type of:
    backup, backup man, fill-in, relief, reliever, stand-in, substitute
    someone who takes the place of another (as when things get dangerous or difficult)
  17. noun
    someone who closely resembles a famous person (especially an actor)
    “he could be Gingrich's double
    synonyms: image, look-alike
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    clone, dead ringer, ringer
    a person who is almost identical to another
    type of:
    individual, mortal, person, somebody, someone, soul
    a human being
  18. verb
    bend over or curl up, usually with laughter or pain
    “He doubled and vomited violently”
    synonyms: double over, double up
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    type of:
    bend, flex
    form a curve
  19. adverb
    downward and forward
    “he was bent double with pain”
  20. verb
    bridge: make a demand for (a card or suit)
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    type of:
    bid, call
    make a demand, as for a card or a suit or a show of hands
  21. adjective
    used of flowers having more than the usual number of petals in crowded or overlapping arrangements
    double chrysanthemums have many rows of petals and are usually spherical or hemispherical”
    see moresee less
    used of flowers having usually only one row or whorl of petals
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