get even vs pay back

get even and pay back both are verbs.

Word	Noun	Adjective	Verb	Adverb
get even	No	No	Yes	No
pay back	No	No	Yes	No

As verbs, pay back is a hyponym of get even; that is, pay back is a word with a more specific, narrower meaning than get even:

Other hyponyms of get even include fix, get, pay off.

get even (verb)	pay back (verb)
compensate; make the score equal	take vengeance on or get even
take revenge or even out a score	act or give recompense in recognition of someone's behavior or actions