an unstable construction with playing cards; "he built three levels of his cardcastle before it collapsed"
a speculative scheme that depends on unstable factors that the planner cannot control; "his proposal was nothing but a house of cards"; "a real estate bubble"
(bridge or whist) the suit that has been declared to rank above all other suits for the duration of the hand; "clubs were declared trumps"; "a trump can take a trick even when a card of a different suit is led"
a playing card in the suit that has been declared trumps; "the ace of trumps is a sure winner"