A board-game ending became a general word for being trapped.
Authoritative answer
Exact answer
Checkmate came through chess vocabulary from Persian and Arabic forms conveying that the king is left helpless or defeated.
Scope: Recorded English etymology and sense history; reviewed July 31, 2026.
Important boundary: The familiar translation 'the king is dead' is an oversimplification; the dictionary's historical note preserves the linguistic uncertainty.