repay vs come back

repay and come back both are verbs.

Word	Noun	Adjective	Verb	Adverb
repay	No	No	Yes	No
come back	No	No	Yes	No

As verbs, repay and come back are synonyms defined as:

Other synonyms of repay include rejoin, retort, return, riposte.

repay (verb)	come back (verb)
answer back	be restored
pay back	go back to something earlier
make repayment for or return something	answer back
act or give recompense in recognition of someone's behavior or actions	even the score, in sports