trump
n. countablen. something that gives you a big advantage over other people. In card games, it is a card from a suit that is stronger than all the others.
n. a playing card of the suit chosen to rank above the others, or any resource used to gain a decisive advantage in a situation. Often used metaphorically to describe a final, winning argument or asset.
She played her trump card and won the debate.
The company's secret patent proved to be the trump that finally forced their competitors to settle the lawsuit.
In the high-stakes world of international diplomacy, access to rare minerals can serve as a trump that outweighs traditional military or economic threats during trade negotiations.
Possibly from French triomphe (“triumph”) or Old French triumphe. If so, it is a doublet of triumph and thriambus. Compare German Trumpf.
From Middle English trumpe, trompe (“trumpet”), from Old French trompe (“horn, trump, trumpet”), from Frankish *trumpa (“trumpet”), from a common Germanic word of imitative origin. Doublet of tulumba and tromp. Akin to Old High German trumpa, trumba (“horn, trumpet”), Middle Dutch tromme (“drum”), Middle Low German trumme (“drum”). More at trumpet, drum.
Ellipsis of Jew's-trump, which may be from French jeu-trompe (literally “toy trumpet”).
Commonly used in the idiomatic phrase 'trump card' to describe a hidden advantage.