Word Origin & History c.1300, from O.Fr. as "one at dice," from
L. as (gen. assis) "a unit," from the name of a small Roman
coin, perhaps originally Etruscan and related to Gk. eis "one."
It meant the side of the die with only one mark before it meant
the playing card. Since this was the lowest roll at dice, ace
was used metaphorically in M.E. for "bad luck;" but as the ace
is often the highest playing card, the extended senses based on
"excellence, good quality" arose 18c. as card-playing became
popular. Meaning "outstanding pilot" dates from 1917
(technically, in WWI aviators' jargon, one who has brought down
10 enemy planes, though originally in ref. to 5 shot down), from
Fr. l'ace (1915), which, according to Bruce Robertson (ed.) "Air
Aces of the 1914-1918 War" was used in prewar Fr. sporting
publications for "top of the deck" boxers, cyclists, etc. Sports
meaning of "point scored" (1819) led to that of "unreturnable
serve" (1889). The verb meaning "to score" (in sports) is first
attested 1923, and led to