trump card
noun/ˈtrʌmp kɑːd/
/ˈtrʌmp kɑːrd/
- (also trump)(in some card games) a card that belongs to the suit (= one of the four sets in a pack of cards) that has been chosen for a particular game to have a higher value than the other three suits
（某些纸牌游戏的一张）王牌，主牌，将牌 - 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
王牌；绝招；杀手锏 - He was able to get what he wanted without having to play his trump card.
他不需要打出王牌，就能得到他想要的东西。 - Many private schools use small classes as their trump card in marketing campaigns.
许多私立学校将小班授课作为营销活动的王牌。
- He was able to get what he wanted without having to play his trump card.