adjective. Having a king in check with no possible move to escape check, thus losing the game.

adjective. Suffering a personal loss with no obvious chance to escape the loss.

verb. Simple past tense and past participle of checkmate.

"Similarly in the modernday, we often use chess as a metaphor of a battle of wits, although I have yet to hear someone say that someone was "checkmated" as a circumlocution for "dead"."

checkmate