drive back vs repulse

drive back is not a noun while repulse is a noun.

Word	Noun	Adjective	Verb	Adverb
drive back	No	No	Yes	No
repulse	Yes	No	Yes	No

As verbs, drive back and repulse are synonyms defined as:

Other synonyms of drive back include fight off, rebuff, repel.

drive back (noun)	repulse (noun)
	an instance of driving away or warding off

drive back (verb)	repulse (verb)
force or drive back	force or drive back
	cause to move back by force or influence
	be repellent to; cause aversion in