I. ace 1 /eɪs/ BrE AmE noun [countable]
[ Date: 1300-1400 ; Language: Old French ; Origin: as , from Latin , 'unit, a small coin' ]
1 . PLAYING CARD a playing card with a single spot on it, which usually has the highest value in a game:
the ace of hearts
I’ve got a pair of aces.
2 . SKILFUL PERSON someone who is extremely skilful at doing something:
a soccer ace
cycling ace Chris Boardman
3 . TENNIS SHOT a first shot in tennis or ↑ volleyball which is hit so well that your opponent cannot reach the ball and you win the point
4 . hold the aces to have the advantages in a situation so that you are sure to win:
The Americans hold most of the aces in this technology.
5 . within an ace of (doing) something very close to doing or achieving something:
The team came within an ace of winning the championship.
6 . have an ace up your sleeve to have a secret advantage which could help you to win or be successful
7 . ace in the hole American English informal something that you keep secretly to use when you need it:
That fifty dollars is my ace in the hole.
II. ace 2 BrE AmE adjective
1 . ace pilot/player/skier etc someone who is a very skilful pilot, player etc:
an ace marksman
2 . British English spoken very good:
The party was ace.
III. ace 3 BrE AmE verb [transitive]
1 . American English informal to do very well in an examination, a piece of written work etc:
I aced the History test.
2 . to hit your first shot in tennis or ↑ volleyball so well that your opponent cannot reach the ball