libellous vs calumnious

libellous and calumnious both are adjectives.

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

As adjectives, libellous and calumnious are synonyms defined as:

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

Other synonyms of libellous include calumniatory, defamatory, denigrating, denigrative, denigratory, libelous, slanderous.

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