stand firm vs defend

stand firm and defend both are verbs.

Word	Noun	Adjective	Verb	Adverb
stand firm	No	No	Yes	No
defend	No	No	Yes	No

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

Other hypernyms of stand firm include fight, fight back, fight down, oppose.

stand firm (verb)	defend (verb)
refuse to abandon one's opinion or belief	argue or speak in defense of
stand up or offer resistance to somebody or something	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