a chess move constituting an inescapable and indefensible attack on the opponent's king
complete victory
place an opponent's king under an attack from which it cannot escape and thus ending the game; "Kasparov checkmated his opponent after only a few moves"
not suitable for a particular occasion etc; "noise seems inappropriate at a time of sadness"; "inappropriate shoes for a walk on the beach"; "put inappropriate pressure on them"
not in keeping with what is correct or proper; "completely inappropriate behavior"