trump card
n. 王牌（最有效的谋略）
同义词
参考例子
1.When his father refused to let him own way, the child played his trump card by crying.
看到爸爸没有如自己的意，那孩子便使出绝招，哇的一声哭了起来。
2.This company has a trump card in the negotiations since it controls most of the stocks.
由于这间公司控制了大部分的股份权，因此在谈判中拥有皇牌。
3.Therefore to establish a powerful navy, especially a submarine fleet as a "trump card", has become the top priority.
因此，组建一支强大的海军，尤其是发展具有“撒手锏”功能的潜艇部队，已成为当务之急。
英文解释
n.
1.a playing card in the suit that has been declared trumps
网络释义
trump card
王牌; 达到目的的最有效手段; 将牌;
trump trump card
王牌;
The Trump Card
制胜王牌;
play their trump card
打出王牌; 用最后的手段; 使出绝招;
play her trump card
打出王牌; 用最后的手段; 使出绝招;