epithet vs calumniation

epithet and calumniation both are nouns.

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

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

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

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

epithet (noun)	calumniation (noun)
descriptive word or phrase	a false accusation of an offense or a malicious misrepresentation of someone's words or actions
a defamatory or abusive word or phrase