n.[C]

1. （纸牌、骰子等的）一；么点，么点牌
2. （网球赛等的）发球得分
3. 【口】王牌，能手，名手，佼佼者[（+at）]
   He is an ace at chess.

   他是个棋艺极精的人。

a.

1. 【口】第一流的，突出的
   He is an ace mechanic. He can repair any cars.

   他是一流的机械师，什么车都会修。

   an ace science fiction writer

   第一流的科幻小说作家

n.

1. a playing card with a single spot on it, the highest card in its suit in most games.
2. informal a person who excels at a particular activity.
3. Tennis  a service that an opponent is unable to return.
4. Golf  a hole in one.

adj.

v.

1. (in tennis) serve an ace against.
2. Golf  score an ace on (a hole).
3. N. Amer. achieve high marks in (a test or exam).