homosexualism vs sex activity

homosexualism and sex activity both are nouns.

Word	Noun	Adjective	Verb	Adverb
homosexualism	Yes	No	No	No
sex activity	Yes	No	No	No

As nouns, sex activity is a hypernym of homosexualism; that is, sex activity is a word with a broader meaning than homosexualism:

homosexualism: a sexual attraction to (or sexual relations with) persons of the same sex
sex activity: activities associated with sexual intercourse

Other hypernyms of homosexualism include sex, sexual activity, sexual practice.

homosexualism (noun)	sex activity (noun)
a sexual attraction to (or sexual relations with) persons of the same sex	activities associated with sexual intercourse