deuce / douce are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
deuce: (noun) a tie in tennis or table tennis that requires winning two successive points to win the game. (noun) one of the four playing cards in a deck that have two spots.
douce: NA
deuce: d·UW·s
douce: NA
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)