'armour' originates from Old French, specifically the word 'armure', where the root 'arm-' is related to Latin 'arma' meaning 'arms' or 'weapons'.

'armour' changed from Old French 'armure' into Middle English 'armure'/'armour' and eventually became the modern English word 'armour' (with the past participle 'armoured').

Initially, it referred to 'arms, equipment or military gear' and later came to mean 'protective covering or defensive metal plates' (and related senses such as being 'protected').