trump card

英 [ˈtrʌmp kɑːd]

美 [ˈtrʌmp kɑːrd]

n. 王牌; 绝招; 杀手锏

牛津词典

noun

王牌；绝招；杀手锏
something that gives you an advantage over other people, especially when they do not know what it is and you are able to use it to surprise them

noun

a playing card in the suit that has been declared trumps
1. the ace of trumps is a sure winner
Synonym:trump

It is always good to enter negotiations with a trump card.
手握一张王牌去谈判总是件好事。
His trump card played, captain lmrie rested his case.
在打出了王牌之后，伊姆里船长便静候分晓。
But China also has a trump card that others don't:$ 3.2 trillion in cash reserves, by far the biggest hoard in the world.
但中国手里握有一张别国不具有的“王牌”：3.2万亿美元的外汇储备，这是全球规模最大的外储。
This is my trump card. I never use it easily.
这可是我的杀手锏，不轻易使用的！
The opponent has to play his trump card to secure his third trick.
对方只好打出将牌以赢得第三墩牌。
Nor can we any longer fall back on our historical trump card of geographic isolation.
我们也不再能依靠天然屏障的历史王牌。
In the end, the Ten took their appeal to the Supreme Court; this, they had believed from the outset, would be their trump card
最后，10个人上诉到最高法院：他们从一开始就认为这一招是他们的王牌。
Not many people know it but shutting up can be the trump card in a lot of situations.
不是每个人都知晓这一点，但沉默在很多场合下的确是最好的王牌。
But the real disappointment for Yahoo shareholders is that the company threw away its trump card so cheaply.
但真正令雅虎股东失望的是，雅虎如此轻易地丢掉了自己的王牌。
I'll play my trump card in the final round.
在最后一局我会出王牌。