linguistics vs homophonous

linguistics is a noun but homophonous is not a noun.

Word	Noun	Adjective	Verb	Adverb
linguistics	Yes	No	No	No
homophonous	No	Yes	No	No

linguistics (noun)	homophonous (noun)
the scientific study of language
the humanistic study of language and literature

linguistics (adjective)	homophonous (adjective)
	characteristic of the phenomenon of words of different origins that are pronounced the same way