Meaning

verb argue or speak in defense of

verb be on the defensive; act against an attack

verb protect against a challenge or attack

originFrom Middle English defenden, from Old French defendre, deffendre (Modern French défendre), from Latin dēfendō (“to ward off”), from Proto-Italic *fendō, ultimately from Proto-Indo-European *gʷʰen-. Displaced native Old English bewerian.

Etymology from Wiktionary, CC BY-SA 3.0