Deuce (dūs), 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.

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.

Deuce, n. [Cf. LL. dusius, Armor, dus, teûz, 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]

• (playing_cards) A card with two spots, one of four in a standard deck of playing cards.
  
• (dice) A side of a dice with two spots
  
• (dice) A cast of dice totalling two
  
• The number two.
  
• (tennis) A tie, both players have the same number of points and one can win by scoring two additional points.
  
• (baseball) A curveball
  
• (epithet) The Devil, used in exclamations of confusion or anger