c. 1300, "mail, defensive covering worn in combat," also, generally, "means of protection," from Old French armeure "weapons, armor" (12c.), from Latin armatura "arms, equipment," from arma "weapons" (including defensive armor), literally "tools, implements (of war)," see arm (n.2). Figurative use in English is from mid-14c.
The meaning "military equipment generally," especially siege engines, is from late 14c. The word might have died with jousting if not for 19c. transference to metal-sheathed combat machinery beginning with U.S. Civil War ironclads (the word first is attested in this sense in an 1855 report from the U.S. Congressional Committee on Naval Affairs). The meaning "protective envelope of an animal" is from c. 1600.
"to cover with armor or armor-plate," mid-15c., from armor (n.). Related: Armored; armoring.
updated on September 25, 2022