push back vs repulse

push back and repulse both are nouns.

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

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

Other synonyms of push back include beat back, drive, force back, repel.

push back (noun)	repulse (noun)
the act of forcing the enemy to withdraw	an instance of driving away or warding off

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