heterosexualism vs heterosexuality

heterosexualism and heterosexuality both are nouns.

Word	Noun	Adjective	Verb	Adverb
heterosexualism	Yes	No	No	No
heterosexuality	Yes	No	No	No

As nouns, heterosexualism and heterosexuality are synonyms defined as:

heterosexualism and heterosexuality: a sexual attraction to (or sexual relations with) persons of the opposite sex

Other synonyms of heterosexualism include straightness.

heterosexualism (noun)	heterosexuality (noun)
a sexual attraction to (or sexual relations with) persons of the opposite sex	a sexual attraction to (or sexual relations with) persons of the opposite sex