Origins
The word 'gender' has one of the most complex and contested semantic histories in the English language. What began as a dry grammatical term has become one of the most debated words of the twenty-first century, and its etymology illuminates how that transformation occurred.
The word entered English in the late fourteenth century from Old French 'gendre' (modern French 'genre'), itself from Latin 'genus' (genitive 'generis'), meaning 'birth,' 'race,' 'kind,' or 'class.' The ultimate root is PIE *ǵenh₁- (to beget). In its earliest English usage, 'gender' was primarily a grammatical term: Latin, French, and other languages assign nouns to classes called 'genders' (masculine, feminine, neuter), and English grammarians needed a word for this classification system.
The grammatical sense was the word's primary meaning for centuries. Latin 'genus' had been used by Roman grammarians (including Varro and Priscian) to describe noun classes, and this technical usage passed through French into English. The three grammatical genders — masculine, feminine, and neuter — did not originally correspond neatly to biological sex; 'genus' meant 'kind' or 'sort,' and grammatical gender was simply a way of sorting nouns into classes, many of which had no connection to sex (Latin 'mensa,' table, is feminine; 'bellum,' war, is neuter).
Development
The use of 'gender' to mean 'the sex of a human being' emerged in the fifteenth century, probably by extension from the grammatical sense: just as nouns had gender (were of a certain 'kind'), so did people. For several centuries, 'gender' and 'sex' were used more or less interchangeably in this meaning, with 'sex' being more common in everyday speech and 'gender' more common in learned or euphemistic contexts.
The modern distinction between 'sex' (biological) and 'gender' (social/cultural) emerged in the mid-twentieth century. The psychologist John Money introduced this distinction in 1955 in the context of intersex research, using 'gender role' to describe the social expectations attached to being male or female. The distinction was developed further by feminist scholars, particularly Simone de Beauvoir (whose 'One is not born, but rather becomes, a woman' anticipated it) and later by Judith Butler, whose 'Gender Trouble' (1990) argued that gender is performative rather than innate.
The word's doublet 'genre' illustrates how the same Latin source can produce different English words with different meanings. 'Genre' was re-borrowed from modern French in the nineteenth century, specifically meaning 'a kind or style of art, music, or literature.' Despite their shared origin, 'gender' and 'genre' occupy completely different semantic fields in contemporary English — one biological and social, the other aesthetic and classificatory.
Proto-Indo-European Roots
The broader word family from Latin 'genus' is enormous: 'general,' 'generate,' 'generous,' 'gentle,' 'genuine,' 'generic,' 'gene,' 'genocide,' 'genealogy,' and dozens more. All descend from the Latin concept of 'kind' or 'birth,' and all ultimately from PIE *ǵenh₁-. The same PIE root produced, through the Germanic branch, English 'kin' and 'kind' — making 'gender' and 'kin' distant cousins.
In twenty-first-century English, 'gender' is simultaneously a grammatical term (in linguistics), a biological category (in medicine), a social construct (in sociology and gender studies), a legal classification (on identity documents), and a site of political contestation. Few words in the language bear such a heavy load of meaning across so many domains, and few words' histories better illustrate how a single Latin root — 'genus,' birth, kind — can ramify across millennia into concepts the original speakers could never have anticipated.