Historical Meaning (OED)
The word gender comes through Old French gendre and Latin genus, meaning “kind,” “sort,” or “class.”
In English, its major historical use was grammatical: nouns were classified as masculine, feminine, or neuter. By the 15th century, it could also refer broadly to males or females considered as a group, essentially overlapping with the older biological meaning of sex. Historically, “gender” did not primarily mean an individual’s psychological identity or a set of socially constructed roles.