Definition of "checkmate"

(chess) Word called out by the victor when making a move that wins the game.  examples

(by extension) Said when one has placed a person in a losing situation with no escape.  examples

The conclusive victory in a game of chess that occurs when an opponent's king is threatened with unavoidable capture.  examples

(figuratively, by extension) Any losing situation with no escape; utter defeat.  examples

(transitive, chess) To put the king of an opponent into checkmate.  examples

(transitive, by extension) To place in a losing situation that has no escape.  examples