Why was clemency trending last week?
1765, in chess, from stale "stalemate" (early 15c.) + mate (n.2) "checkmate." Middle English stale is probably from Anglo-French estale "standstill" (see stall (n.2)). A misnomer, because a stale is not a mate. "In England from the 17th c. to the beginning of the 19th c. the player who received stalemate won the game" [OED]. Figurative sense is recorded from 1885.