The conclusive victory in a game of chess that occurs when an opponent's king is threatened with unavoidable capture.
(by extension) Any losing situation with no escape; utter defeat.
To put the king of an opponent into checkmate.
That jerk checkmated me in four moves!
(by extension) To place in a losing situation that has no escape.
Word called out by the victor when making a move that wins the game.
(by extension) Said when one has checkmated someone (placed them in a losing situation with no escape.)