—n. 1. Also called mate.Chess. a. an act or instance of maneuvering the opponent's king into a check from which it cannot escape, thus bringing the game to a victorious conclusion.
b. the position of the pieces when a king is checkmated.
2. a complete check; defeat: His efforts to escape met with a checkmate.
—v.t. 1. Chess.to maneuver (an opponent's king) into a check from which it cannot escape; mate.
2. to check completely; defeat: Napoleon was checkmated at Waterloo.
—interj. Chess.(used by a player to announce that he or she has put the opponent's king into inextricable check.)