1
- a playing card with a single spot on it, ranked as the highest card in its suit in most card games.A纸牌（在多数牌戏中为最大牌）：
the ace of diamonds
方块A
figurative〈喻〉life had started dealing him aces again.
生活又开始眷顾他了。
2
- often with modifier informal a person who excels at a particular sport or other activity〈非正式〉成绩超群的人, 佼佼者：
a motorcycle ace.
王牌摩托车手。
2.1
- a pilot who has shot down many enemy aircraft（击落多架敌机的）王牌飞行员。
3
- (in tennis and similar games) a service that an opponent is unable to return and thus wins a point（网球等比赛用语）ace球; 发球得分。
3.1
- Golf, informal a hole in one【高尔夫】〈非正式〉一杆进洞。
- informal very good〈非正式〉一流的, 杰出的：
an ace swimmer
一流的游泳选手
as an exclamation Ace! You've done it!好极了！你成功了！
with obj.
1- informal (in tennis and similar games) serve an ace against (an opponent)〈非正式〉（网球等比赛用语）以ace球对付, 以发球赢（对手）一分。
1.1
- Golf score an ace on (a hole) or with (a shot)【高尔夫】在（某洞）上一杆进洞; 以（某次击球）得分。
1.2
- N. Amer. get an A or its equivalent in (a test or exam)〈北美〉（在测验或考试中）得A, 得优：
I aced my grammar test.
我语法考了个A.
1.3
ace someone out
N. Amer. outdo someone in a competitive situation〈北美〉（在竞争场合）胜过（某人）：it wasn't our intention to ace Phil out of a job.
我们并不想胜过菲尔, 让他丢工作。
短语
ace up one's sleeve（或〈北美〉in the hole）
- a plan or piece of information kept secret until it becomes necessary to use it手中握有王牌; 有应急妙计。
hold all the aces
- have all the advantages占尽优势。
play one's ace
- use one's best resource打出王牌; 使出绝招：
deciding to play her ace, Emily showed the letter to Vic.
埃米莉决定使出杀手锏, 把信拿给维克看。
within an ace of
- very close to差点儿, 几乎：
they came within an ace of death.
他们差点儿就死了。
词源
Middle English （denoting the & oq.one& cq. on dice）： via Old French from Latin as 'unity, a unit'.