From Middle English mate, a borrowing from Middle Low German mate (replacing Middle English mette, from Old English ġemetta), derived from Proto-Germanic *gamatjô, itself from *ga- (related to German and Dutch ge-) + *matjô (from *matiz), related to Old English mete). From the same Middle Low German source stems German Maat. Cognates include Saterland Frisian Moat, Dutch maat. More at Old English ġe-, English co-, English meat. maat.
From Middle English verb maten, from Middle French mater, from Old French noun mat, from Persian شاه مات.
From Middle English maten, from Old French mater, from Vulgar Latin *mattō, of unclear origin.