calumnious vs calumny

calumnious is not a noun while calumny is a noun.

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

calumnious (noun)	calumny (noun)
	an abusive attack on a person's character or good name
	a false accusation of an offense or a malicious misrepresentation of someone's words or actions

calumnious (adjective)	calumny (adjective)
(used of statements) harmful and often untrue; tending to discredit or malign