epithet vs calumny

epithet and calumny both are nouns.

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

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

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

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

epithet (noun)	calumny (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