noun a complete check; utter defeat or overthrow.
2. checkmate ·vt to defeat completely; to terminate; to thwart.
3. checkmate ·noun the position in the game of chess when a king is in check and cannot be released, which ends the game.
4. checkmate ·vt to check (an adversary's king) in such a manner that escape in impossible; to defeat (an adversary) by putting his king in check from which there is no escape.