lesbian vs gay

lesbian and gay both are nouns.

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

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

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

lesbian (noun)	gay (noun)
a female homosexual	someone who is sexually attracted to persons of the same sex

lesbian (adjective)	gay (adjective)
of or relating to or characterized by homosexual relations between woman	bright and pleasant; promoting a feeling of cheer
	brightly colored and showy
	homosexual or arousing homosexual desires
	given to social pleasures often including dissipation
	offering fun and gaiety
	full of or showing high-spirited merriment