ward off vs defend

ward off and defend both are verbs.

Word	Noun	Adjective	Verb	Adverb
ward off	No	No	Yes	No
defend	No	No	Yes	No

As verbs, defend is a hypernym of ward off; that is, defend is a word with a broader meaning than ward off:

ward off (verb)	defend (verb)
avert, turn away, or repel	argue or speak in defense of
prevent the occurrence of; prevent from happening; to protect from or to keep away anything undesirable; to ward off	state or assert
	be on the defensive; act against an attack
	protect against a challenge or attack
	protect or fight for as a champion
	fight against or resist strongly
	be the defense counsel for someone in a trial