gender binary

[ jen-der bahy-nuh-ree, ‐ner-ee ]
/ ˈdʒɛn dər ˌbaɪ nə ri, ‐nɛr i /

noun

a classification system consisting of two genders, male and female.
a concept or belief that there are only two genders and that one's biological or birth gender will align with traditional social constructs of masculine and feminine identity, expression, and sexuality.

Origin of gender binary

First recorded in 1980–90