What does sex mean?
Sex has several related meanings. As a count noun, it can refer to the biological categories commonly described as male and female, especially in scientific, medical, or comparative contexts. It can also mean sexual activity, as in “have sex,” although it is usually uncountable in that use. A third, less formal meaning denotes sexual attractiveness, as when someone is described as having sex appeal. The word appears in both everyday and clinical language, ranging from sex education and sexual health to historical or literary descriptions of sexual conduct. Although modern usage is sensitive to distinctions between biological sex, gender, sexuality, and related personal identities, those concepts are not interchangeable. As a verb, “to sex” once meant to engage in sexual intercourse with someone, but that usage now sounds archaic except in older or deliberately literary writing.
A biological category, especially either of the two categories commonly called male and female; the activity of sexual intercourse; or sexual attractiveness.
"The exhibit explains how biological sex varies across species."
The biological sense is commonly countable, while the sense meaning sexual activity is generally uncountable.
To engage in sexual intercourse with someone.
"The archaic novel describes how the characters secretly sex each other."
This use is now archaic or literary and is uncommon in contemporary speech.
Use the plural when referring to the two biological categories collectively or individually; sexual activity itself is normally uncountable.
"The study compared reproductive biology in males and females across several species."
The word descended from a Latin term meaning “state” or “condition,” before English narrowed its meaning to human sexuality and biological sex.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does sex come from?
The English word comes through Old French sexe from Latin sexus, a term originally meaning “state,” “condition,” or “nature.” Over time, Latin sexus came to refer specifically to the distinction between male and female, and English later extended the word to sexual activity and attractiveness. Modern English forms such as sexual, sexuality, and sexually were subsequently derived from the established English noun.
Related word forms
How sex is actually used
In modern usage, sex is usually neutral as a count noun when referring to biological categories, although it may be pluralized when contrasting categories. It is also commonly used as an uncountable noun for sexual activity. The older expression “the sex,” meaning people of a particular biological category, can sound clinical or archaic in some contexts. As a verb, sex is now rarely used and is generally literary or archaic.
Easily confused with sex
The number six is pronounced /sɪks/, whereas sex is pronounced /seks/.
Sex commonly refers to biological categories, while gender refers to social and cultural identities.