late 15c., "a roll of 2 in dice," from M.Fr. deus, from L. duos (nom. duo) "two." 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 L. deus and related words meaning "god." Low Ger. had der daus! in same sense 16c., which probably influenced the Eng. form. Deuce coup is 1940s hot-rodder slang for "souped up two-door car," especially a 1932 Ford.