n.
- a playing card with a single spot on it, the highest card in its suit in most games.
- informal a person who excels at a particular activity.
- Tennis a service that an opponent is unable to return.
- Golf a hole in one.
adj.
informal very good.
v.
informal - (in tennis) serve an ace against.
- Golf score an ace on (a hole).
- N. Amer. achieve high marks in (a test or exam).
Phrase
- ace up one's sleeve
(or N. Amer. in the hole)
something effective kept in reserve. - hold all the aces
have all the advantages. - within an ace of
very close to.
Etymology
ME (denoting the ‘one’ on dice): via OFr. from L. as ‘unity, a unit’.