Green’s Dictionary of Slang

1. a condom; thus fight in armour v., to have intercourse using a condom; armorial adj.

1708		J. Browne Almonds for Parrots 5: Achilles Armour cannot match with thine.
1728		W. Pattison ‘Kundumogenia’ in Poetical Works 96: [Venus’s warriors have] new Armour [...] a Coat of Mail [...] soft, and pliant as a Glove.
1732		Progress of a Rake 40: Our Youth too often find ’em [i.e. whores] stale, / And sting without a Coat of mail.
1741		W. Kennett ‘Armour’ in Potent Ally 3: The hot daring Youth, whose giddy Lust [...] Resolves upon Fruition, unimpare’d / By intervening Armour, C----m hight! [Ibid.] 5: [footnote] Colonel Condom was the Inventor of What is vulgarly called a C----m, alias armour, by the Girls of the Town, and who generally carry this Defence about them, at 1 s. each.
1763		Boswell London Journal 9 Apr. n.p.: Then came to the Park, and in armorial guise performed concubinage with a strong, plump, good-humoured girl. [Ibid.] 17 May n.p.: We went down a lane to a snug place, and I took out my armour, but she begged that I might not put it on, as the sport was much pleasanter without it.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: to fight in armour, to make use of Mrs. Philip’s ware. See c—d—m.
1811		Lex. Balatronicum.

2. (UK gang) weapons, thus armoured, armed.

2018-20

T. Thorne (ed.) ‘Drill Slang Glossary’ at Forensic Linguistic Databank 🌐 Armour – weapons [...] Armoured - armed.