checkmate Look up checkmate at Dictionary.com
c.1346, from O.Fr. eschec mat, ult. from Pers. shah mat, lit. "the king is left helpless," from shah "king" + mat "he is dead."
stalemate Look up stalemate at Dictionary.com
1765, in chess, from stale "stalemate" (1425) + mate "checkmate" (see checkmate). M.E. stale is probably from Anglo-Fr. estale "standstill" (see stall (2)). A misnomer, since 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]. Fig sense is recorded from 1885.
matador Look up matador at Dictionary.com
1674, from Sp. matador, lit. "killer," from matar "to kill or wound," probably from Arabic mata "he died," from Persian (see second element in checkmate).
mate (n.) Look up mate at Dictionary.com
"companion, associate, fellow, comrade," c.1380, from M.L.G. mate, gemate "one eating at the same table, messmate," from P.Gmc. *ga-maton "having food (*matiz) together (*ga-)," which is etymologically identical with companion (q.v.). Meaning "one of a wedded pair" is attested from 1549. Used as a form of address by sailors, laborers, etc., since at least 1450. Meaning "officer on a merchant vessel is from 1496. The verb, of animals, "to pair for the purpose of breeding" is first recorded 1601. The verb in chess (c.1320) is short for checkmate (q.v.) and is not related.