lesbian vs woman

lesbian and woman both are nouns.

Word	Noun	Adjective	Verb	Adverb
lesbian	Yes	Yes	No	No
woman	Yes	No	No	No

As nouns, woman is a hypernym of lesbian; that is, woman is a word with a broader meaning than lesbian:

Other hypernyms of lesbian include gay, homo, homophile, homosexual, adult female.

lesbian (noun)	woman (noun)
a female homosexual	women as a class
	an adult female person (as opposed to a man)
	a female person who plays a significant role (wife or mistress or girlfriend) in the life of a particular man

lesbian (adjective)	woman (adjective)
of or relating to or characterized by homosexual relations between woman