trump card

American  

[truhmp kahrd, truhmp kahrd] / ˈtrʌmp ˌkɑrd, ˈtrʌmp ˈkɑrd /

noun

1. Cards. trump.

2. Informal. something that gives one person or group the advantage over another.

   The surprise witness was his trump card.

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trump card Cultural  

1. In general, something capable of making a decisive difference when used at the right moment; in certain card games, trump is the suit designated as having precedence over the others: “The prosecutor was about to win the case, when the defense lawyer produced her trump card: an eyewitness who testified that the accused was nowhere near the scene of the crime.”

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trump card Idioms  

1. A key resource to gain an advantage at the opportune moment, as in That surprise witness was the defense's trump card, or She played her trump card, announcing that the Senator would speak. This expression transfers the trump card of games such as bridge, which can win over a card of another suit, to other kinds of advantage. [Early 1800s]

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Etymology

Origin of trump card

First recorded in 1815–25

Example Sentences

Mr. Johnson holds a trump card of sorts.

From New York Times

Ms. Elgison, however, still has a trump card she hopes might work.

From New York Times

But it is also true that the government has a trump card to play in this debate - and we can expect them to play it often.

From BBC

“But it doesn’t have any trump card in its hand to increase its market share. SAP is in defence mode. And the hyperscalers are sucking away the innovation budgets of SAP’s customers.”

From Reuters

These moves amount to an attempt to election-proof conservative control, reserving for the right the ultimate trump card that would block legislative and electoral shifts needed to rebalance democratic fairness and advance progressive policies.

From The Guardian