The Collaborative International Dictionary of English v.0.48:

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]

The Collaborative International Dictionary of English v.0.48:

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]

WordNet (r) 3.0 (2006):

deuce
    n 1: a tie in tennis or table tennis that requires winning two
         successive points to win the game
    2: the cardinal number that is the sum of one and one or a
       numeral representing this number [syn: two, 2, II,
       deuce]
    3: a word used in exclamations of confusion; "what the devil";
       "the deuce with it"; "the dickens you say" [syn: devil,
       deuce, dickens]
    4: one of the four playing cards in a deck that have two spots
       [syn: deuce, two]

Moby Thesaurus II by Grady Ward, 1.0:

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