The DICT Development Group

  Deuce \Deuce\ (d[=u]s), n. [F. deux two, OF. deus, fr. L. duo.
     See Two.]
     1. (Gaming) Two; a card or a die with two spots; as, the
        deuce of hearts.
        [1913 Webster]
  
     2. (Tennis) A condition of the score beginning whenever each
        side has won three strokes in the same game (also reckoned
        "40 all"), and reverted to as often as a tie is made until
        one of the sides secures two successive strokes following
        a tie or deuce, which decides the game.
        [1913 Webster]

  Deuce \Deuce\, n. [Cf. LL. dusius, Armor, dus, te[^u]z, phantom,
     specter; Gael. taibhs, taibhse, apparition, ghost; or fr. OF.
     deus God, fr. L. deus (cf. Deity).]
     The devil; a demon. [A euphemism, written also deuse.]
     [Low]
     [1913 Webster]

  36 Moby Thesaurus words for "deuce":
     ace, best bower, bower, cards, clubs, craps, deck, diamonds,
     doubleton, dummy, face cards, flush, full house, hand, hearts,
     jack, joker, king, knave, left bower, pack, pair, picture cards,
     playing cards, queen, round, royal flush, rubber, ruff, singleton,
     snake eyes, spades, straight, trey, trick, trump