contradictory vs antonymous

contradictory is a noun but antonymous is not a noun.

Word	Noun	Adjective	Verb	Adverb
contradictory	Yes	Yes	No	No
antonymous	No	Yes	No	No

contradictory (noun)	antonymous (noun)
two propositions are contradictories if both cannot be true (or both cannot be false) at the same time

contradictory (adjective)	antonymous (adjective)
of words or propositions so related that both cannot be true and both cannot be false	of words: having opposite meanings
unable for both to exist or be true at the same time
in disagreement
that confounds or contradicts or confuses