1. trump card - Noun
2. trump card - Phrase
(card games) A playing card, of the trump suit that is held in reserve until needed to win a trick.
(figuratively) Something used to obtain an advantage, sometimes unscrupulously.
Source: en.wiktionary.orgAgain, if a player does not have any cards of the lead suit and can play a trump card higher than any other trump played so far, the player must do so, even if the player expects that a later player will beat the card. Source: Internet
Fresh from a promising campaign in the 2020 U19 World Cup for Pakistan, Aamir Ali could turn out to be an unlikely trump card for Peshawar. Source: Internet
Certain games are "play to beat" or "must-trump"; if a player cannot follow suit but can play trump, they must play trump, and additionally if they are able they must beat any trump card already played to the trick. Source: Internet
Master coach plays trump card against a Blues team holding all the acesEven by his mercurial standards, this 18-14 win over NSW surely ranks among Wayne Bennett's great coaching performances. Source: Internet
Itachi can easily beat Deku using his trickeries without having to use his ultimate trump card, the Mangekyo Sharingan. Source: Internet
If another trump has already been played that a player cannot beat, then they can play any trump in their hand, but they still must play a trump card if they can. Source: Internet