cuckold vs cheat on

cuckold is a noun but cheat on is not a noun.

Word	Noun	Adjective	Verb	Adverb
cuckold	Yes	No	Yes	No
cheat on	No	No	Yes	No

As verbs, cuckold and cheat on are synonyms defined as:

cuckold and cheat on: be sexually unfaithful to one's partner in marriage

Other synonyms of cuckold include betray, cheat, wander.

cuckold (noun)	cheat on (noun)
a man whose wife committed adultery

cuckold (verb)	cheat on (verb)
be sexually unfaithful to one's partner in marriage	be sexually unfaithful to one's partner in marriage