a small piece of stiff paper that is marked with symbols or pictures to show its value, comes in a set, and is used for playing games (such as poker) —called also playing card
a game played with a deck of cards : a card game
—used figuratively to refer to something that gives you an advantage when you are trying to make a deal or reach an agreement
2cardverb
to ask (someone) to show a form of identification (such as a driver's license) in order to prove that the person is old enough to do something (such as to drink alcohol)