a playing card, face of a dice, or domino marked with one spot or pip
the single spot or pip on any of these
a shot, esp a service in tennis, that an opponent fails to reach
a point scored by such a shot
informal an expert or leading performer in a specified field
a combat pilot who has brought down five or more enemy aircraft
chiefly NAmer in golf, a hole in one (see hole1)
ace in the hole
NAmer an effective argument or resource held in reserve
[a term in stud poker for an ace dealt face down so that its value is concealed]ace up one's sleeve
an effective argument or resource held in reserve
hold all the aces
to have all the advantages or initiative
within an ace of
on the point of; very near to
[Middle English as via Old French from Latin as a unit, a copper coin]