sex

1. (countable) A category into which sexually-reproducing organisms are divided on the basis of their reproductive roles in their species; the system of such categories, which can differ by organism or by taxonomic branch.Examples: "The effect of the medication is dependent upon age, sex, and other factors."; "The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of sex."; "I would never have guessed […] that slime molds can have thirteen sexes."Synonyms: gendercountable

2. (countable) Another category, especially of humans and especially based on sexuality or gender roles.Examples: "Still there are some loop-holes out of which a man may creep, and dare to think and act for himself; but for a woman it is an herculean task, because she has difficulties peculiar to her sex to overcome, which require almost super-human powers."; ""But now another sex, in arms, is brought, / And, realms to guard, are eunuchs able thought!""; "A black old neutral personage / Of the third sex stept up."countable

3. (countable) The members of such a category, taken collectively.Examples: "the fairer sex"; "It was a weakness / In me, but incident to all our sex."; "The sensibility of the female sex appears […] to be greater than that of the male."countable

4. (uncountable) The distinction and relation between these categories, especially in humans; gender.Examples: "A lot of women now like men to pay for them on dates... We've dealt with the outdated view of sex underpinning this."uncountable

5. (obsolete or literary, uncountable, with "the") Women; the human female gender and those who belong to it.Examples: "The sex of Venice are undoubtedly of a distinguished beauty."; "I was not, however, better than my neighbors; the Sex had its charms for me as it had for others; But there always remained a sting, that time only wore away."; "Even the reptile temperament of Noel Vanstone warmed under the influence of the sex: he had an undeniably appreciative eye for a handsome woman, and Magdalen's grace and beauty were not thrown away on him."literaryobsoleteuncountablewith-definite-article

6. (uncountable) Sexual activity, usually sexual intercourse unless preceded by a modifier.Examples: "We marry in fear and trembling, sex for a home is the woman's traffic, and the man comes to his heart's desire when his heart's desire is dead."; "If you want to have sex, you've got to trust / At the core of your heart, the other creature."; "1934, translation of the Qur'an (23:5) by Abdullah Yusuf Ali (The believers ... those ... ) who abstain from sex"uncountable