discard

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To throw away; reject.
• intransitive verb To throw out (a playing card) from one's hand.
• intransitive verb To play (a card other than a trump) from a suit different from that of the card led.
• intransitive verb To discard a playing card.
• noun The act of discarding in a card game.
• noun A discarded playing card.
• noun One that is discarded or rejected.

from The Century Dictionary.

• noun In poker, the pile of cards made up by the hands which are abandoned without being bet upon, and the cards which have been laid off so as to get others in exchange for them.
• In card playing: In some games, to throw aside or reject from the hand, as a card dealt to the player which by the laws of the game is not needed or can be exchanged.
• In other games, as whist, to throw away on a trick, as a card (not a trump) of a different suit from that led, when one cannot follow suit and cannot or does not wish to trump
• To dismiss, as from service or employment; cast off.
• To thrust away; reject: as, to discard prejudices.
• Synonyms To turn away, discharge.
• In card-playing, to throw cards out of the hand. See I.
• noun In card-playing: The act of throwing out of the hand such cards as are unnecessary in the game, or of playing, as in whist, a card not a trump of a different suit from that led.
• noun The card or cards thrown out of the hand.
• noun Hence One who or that which is cast out or rejected.

from the GNU version of the Collaborative International Dictionary of English.

• intransitive verb (Card Playing) To make a discard.
• noun (Card Playing) The act of discarding; also, the card or cards discarded.
• transitive verb (Card Playing) To throw out of one's hand, as superfluous cards; to lay aside (a card or cards).
• transitive verb To cast off as useless or as no longer of service; to dismiss from employment, confidence, or favor; to discharge; to turn away.
• transitive verb To put or thrust away; to reject.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb transitive to throw away, to reject
• noun Anything discarded.
• noun A discarded playing card in a card game.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb throw or cast away
• noun getting rid something that is regarded as useless or undesirable
• noun anything that is cast aside or discarded
• noun (cards) the act of throwing out a useless card or of failing to follow suit