homologous vs homology

homologous is not a noun while homology is a noun.

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

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

homologous (adjective)	homology (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