1900; see heterosexual + -ity.
heterosexuality het·er·o·sex·u·al·i·ty (hět'ə-rō-sěk'shōō-āl'ĭ-tē)
n.
Erotic attraction, predisposition, or sexual behavior between persons of the opposite sex.
Sexual attraction between a male and a female. (Compare bisexuality and homosexuality.)