Origin: 1250–1300; Middle English armo(u)r, armure < Anglo-French armour(e), armureOld French armëure < Latin armātūraarmature; assimilated, in Middle English and Anglo-French, to nouns ending in -our-or2
c.1300, "mail, defensive covering worn in combat," from O.Fr. armeure (12c.), from L. armatura "arms, equipment," from arma "arms, gear" (see arm (2)). The word might have died with jousting if not for late 19c. transference to metal-shielded machinery beginning with U.S. Civil