Monosexuality
Monosexuality refers to a sexual orientation in which a person is sexually attracted to only one gender or gender identity. This includes, for example, heterosexual and homosexual people. The term is often used as the counterpart to bisexual, pansexual, or multisexual, although it is not always common in everyday language.
It is important to distinguish monosexuality from romantic orientation: monosexuality describes sexual, not necessarily romantic, attraction. It is also not the same as monogamy, which is a relationship structure. The exact meaning depends on the context.