deuce [LME] The two different meanings of deuce both come from Latin duus ‘two’, by different routes. The earliest meaning, from the late 15th century, was ‘a throw of two at dice’. The immediate source was the French word for ‘two’ (modern deux). In the mid 17th century this was reinforced by German duus, meaning ‘bad luck or mischief’ and by association ‘the devil’. The connection arose because two is the worst or unluckiest throw you can have when playing with two dice. Expressions where deuce is interchangeable with *devil (as in ‘where the deuce…’ or ‘a deuce of a…’) are now rather old-fashioned. In the late 16th century, deuce was a stage in the original form of tennis, now known as real tennis, which is played with a solid ball on an enclosed court. In real tennis deuce is five or more games all when two successive points had to be won by a player to win.