Entries related to a deux
word-forming element expressing direction toward or in addition to, from Latin ad "to, toward" in space or time; "with regard to, in relation to," as a prefix, sometimes merely emphatic, from PIE root *ad- "to, near, at."
Simplified to a- before sc-, sp- and st-; modified to ac- before many consonants and then re-spelled af-, ag-, al-, etc., in conformity with the following consonant (as in affection, aggression). Also compare ap- (1).
In Old French, reduced to a- in all cases (an evolution already underway in Merovingian Latin), but written forms in French were refashioned after Latin in 14c. and English did likewise 15c. in words it had picked up from Old French. In many cases pronunciation followed the shift. Over-correction at the end of the Middle Ages in French and then English "restored" the -d- or a doubled consonant to some words that never had it (accursed, afford). The process went further in England than in France, where the vernacular sometimes resisted the pedantic, resulting in English adjourn, advance, address, advertisement (Modern French ajourner, avancer, adresser, avertissement). In modern word-formation sometimes ad- and ab- are regarded as opposites, but this was not in classical Latin.
late 15c., dews, "the 2 in dice or cards," also "a roll of 2 in dice" (1510s), from Old French deus (Modern French deux), from Latin duos (nominative duo) "two" (from PIE root *dwo- "two"). The spelling -ce from -s to reflect voiceless pronunciation is as in dice, pence, etc.
The word became a mild oath by 1710, about 50 years after it was first attested in the sense of "bad luck, the devil, etc.," perhaps because two was the lowest score, and probably by similarity to Latin deus and related words meaning "god." According to OED, 16c. Low German had der daus! in the same sense, which perhaps influenced the English form.
In tennis, "a stage of the game in which both players or sides have scored 40, and one must score 2 points to win," 1590s. Deuce coupe is 1940s hot-rodder slang for "souped up two-door car," especially a 1932 Ford. Related: Deuced; deucedly.