1 a [count] : 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) ▪ Each player is dealt five cards. ▪ Shuffle the cards. ▪ card tricks ▪ He bought a deck/pack of cards. ▪ poker and other card games [=games that use a deck of cards] —called also playing card; —see also cardsharp, card table, face card, house of cards, picture card b cards [plural] : a game played with a deck of cards : a card game ▪ Do you want to play (a game of) cards? ▪ We played cards until midnight. c [count] —used figuratively to refer to something that gives you an advantage when you are trying to make a deal or reach an agreement ▪ The fact that he was supported by big firms was his strongest/best card during the negotiations. d [singular] —used figuratively to refer to an emotional issue (such as race) that is mentioned in a particular situation in order to give you an advantage ▪ She used/played the gender card and said we didn't hire her because she's a woman. ▪ She was accused of playing the race card to defend her client. [=she was accused of saying that her client was treated unfairly because of his race]
2 [count] a : a thick piece of paper that is usually folded in half and decorated on one side and that contains a greeting, an invitation, etc. ▪ He sent me a card for my birthday. = He sent me a birthday card. ▪ a get well card ▪ a card shop/store —see also christmas card, greeting card b : postcard ▪ She sent us a card from Japan.
3 [count] : a rectangular piece of plastic that is used to buy goods or services or to get money from a bank or a machine ▪ “Will you be paying cash?” “No, please put it on my card.” [=I will pay for it using my credit/debit card] ▪ an ATM card ▪ Insert your card into the machine. = Swipe/Pass your card through the machine.
4 [count] a : a rectangular piece of paper or plastic with information about a person written on it ▪ a membership/library/appointment card ▪ Let me give you my card. [=business card] b : a small piece of paper that is used for writing down information ▪ He wrote his notes on 3 x 5 cards. [=cards that are 3 inches tall and 5 inches wide] ▪ You may use note cards [=cards with notes on them] during your speech.
5 [count] : trading card ▪ a collection of baseball/football/basketball cards
6 [count] : a thin, hard board that has small electronic devices on it and that can be added to the inside of a computer to make the computer perform different tasks ▪ a memory/sound/video card ▪ an expansion card [=a device that allows a computer to do more things than it originally could]
7 [count] : a list of the individual competitions that will happen at a sports event : a sports program ▪ a racing card [=a list of races] ▪ a boxing card [=a list of boxing matches] ▪ Three fights are on the card tonight.
8 [count] old-fashioned : a funny or amusing person ▪ He's such a card!
9 [noncount] Brit : cardboard ▪ a piece of card