homology vs homologous

homology is a noun but homologous is not a noun.

Word	Noun	Adjective	Verb	Adverb
homology	Yes	No	No	No
homologous	No	Yes	No	No

homology (noun)	homologous (noun)
the quality of being similar or corresponding in position or value or structure or function

homology (adjective)	homologous (adjective)
	corresponding or similar in position or structure or function or characteristics; especially derived from an organism of the same species
	having the same evolutionary origin but not necessarily the same function