homosexuality vs gayness

homosexuality and gayness both are nouns.

Word	Noun	Adjective	Verb	Adverb
homosexuality	Yes	No	No	No
gayness	Yes	No	No	No

As nouns, homosexuality and gayness are synonyms defined as:

homosexuality and gayness: a sexual attraction to (or sexual relations with) persons of the same sex

Other synonyms of homosexuality include homoeroticism, homosexualism, queerness.

homosexuality (noun)	gayness (noun)
a sexual attraction to (or sexual relations with) persons of the same sex	a sexual attraction to (or sexual relations with) persons of the same sex