epithet vs defamation

epithet and defamation both are nouns.

Word	Noun	Adjective	Verb	Adverb
epithet	Yes	No	No	No
defamation	Yes	No	No	No

As nouns, defamation is a hypernym of epithet; that is, defamation is a word with a broader meaning than epithet:

epithet: a defamatory or abusive word or phrase
defamation: a false accusation of an offense or a malicious misrepresentation of someone's words or actions

Other hypernyms of epithet include calumniation, calumny, hatchet job, obloquy, traducement.

epithet (noun)	defamation (noun)
descriptive word or phrase	an abusive attack on a person's character or good name
a defamatory or abusive word or phrase	a false accusation of an offense or a malicious misrepresentation of someone's words or actions