gay vs queer

gay and queer both are nouns.

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

As adjectives, gay and queer are synonyms defined as:

Other synonyms of gay include homophile.

As nouns, queer is a hyponym of gay; that is, queer is a word with a more specific, narrower meaning than gay:

gay (noun)	queer (noun)
someone who is sexually attracted to persons of the same sex	offensive term for a homosexual man

gay (adjective)	queer (adjective)
bright and pleasant; promoting a feeling of cheer	homosexual or arousing homosexual desires
brightly colored and showy	beyond or deviating from the usual or expected
homosexual or arousing homosexual desires
given to social pleasures often including dissipation
offering fun and gaiety
full of or showing high-spirited merriment

gay (verb)	queer (verb)
	put in a dangerous, disadvantageous, or difficult position
	hinder or prevent (the efforts, plans, or desires) of