Checkmate \Check"mate\ (-m[=a]t), v. t. [imp. & p. p. {Checkmated}; p. pr. & vb. n. {Checkmating}.] 1. (Chess) 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. [1913 Webster] 2. To defeat completely; to terminate; to thwart. [1913 Webster] To checkmate and control my just demands. --Ford. [1913 Webster]