trump card

剑桥词典

an advantage that makes you more likely to succeed than other people , especially something that other people do not know about
独有的优势，独门法宝；王牌；绝招
Anthea was about to play her trump card - without her signature none of the money could be released . 安西娅准备打出她的王牌——没有她的签字，一分钱也不能动。 返回 trump card