Definition of sex in English:



  • 1[mass noun] (chiefly with reference to people) sexual activity, including specifically sexual intercourse:

    ‘he enjoyed talking about sex’
    ‘she didn't want to have sex with him’
    • ‘Janet Charlton said Daniel O'Brien frequently spoke to her about group sex during their sexual activities together.’
    • ‘Vaccination is recommended for sexually active men who have sex with men.’
    • ‘She did not wish to have sex with him and did not consent to sexual intercourse.’
    • ‘In studies from the United Kingdom, the incidence and prevalence are lower in women who have sex with women than heterosexual women, but they are still at risk.’
    • ‘If you want to have sex with your ex just because you feel guilty, reconsider your intentions.’
    • ‘He may be getting turned on watching them, but it's you he wants to have sex with.’
    • ‘It's the married person's job not to cheat, not other people's duty to refuse to have sex with them.’
    • ‘Of course many are of the opinion that better sex education should be taught in schools.’
    • ‘He's a few years older than me, so right off the bat I told him I am not going to have sex with him, and I'm not.’
    • ‘In fact, there have been times when I wanted to have sex with guys, but they didn't want to.’
    • ‘While men have sex with men everywhere, how people perceive that varies widely.’
    • ‘So I can understand the temptation to put all our resources into preventing HIV among men who have sex with men.’
    • ‘Not enough of sex education in schools is focused on what happens if you do get pregnant.’
    • ‘It is important to find a man who's good in bed and who loves to have sex with you.’
    • ‘I think she's curious herself - curious about love and sex and sexuality.’
    • ‘These early ideas have had a powerful influence on our views of sex and sexuality.’
    • ‘Often couples find themselves with emotional intimacy but gradually diminishing sex lives or no sex at all.’
    • ‘The staff can be extremely helpful, providing lots of explicit sex education without a trace of shame.’
    • ‘Finally, it would be ideal to wait to have sex with that one person you are married to for life.’
    • ‘On the flip side, do we consider women who have sex with under-age boys to be paedophiles as well?’
    seduce, rape, ravish
    do it, do the business, go all the way, make whoopee, have one's way with, bed, know in the biblical sense, tumble
    bonk, get one's oats
    fuck, screw, bang, lay, get one's leg over, shaft, dick, frig, do, have, hump, poke, shtup, dip one's wick, ride, service, tup
    shag, knob, get one's end away, knock someone off, give someone one, roger, grind, stuff
    ball, jump, jump someone's bones, bone, pork, diddle, nail
    possess, lie together, lie with, swive, know
    sexual intercourse, intercourse, lovemaking, making love, sex act, sexual relations, anal penetration, sexual penetration, vaginal penetration
    the facts of life, sexual reproduction, reproduction
    sleep together, sleep with, go to bed together, go to bed with
    View synonyms
    1. 1.1euphemistic [in singular] A person's genitals.
  • 2Either of the two main categories (male and female) into which humans and most other living things are divided on the basis of their reproductive functions:

    ‘adults of both sexes’
    • ‘For the purpose of this statute, it is understood that the term gender refers to the two sexes, male and female, within the context of society.’
    • ‘There has also been a growing recognition that the biological differences between the sexes extend beyond the reproductive.’
    • ‘I wonder whether this is part of the reason that the belief that there are two and only two human sexes persists?’
    • ‘The two great sexes of male and female, says Milton, animate the world.’
    • ‘The difference between the sexes remains the main reason for male preference for women in their teens and twenties.’
    • ‘The male and female sexes grew out of this advantage over the subsequent millions of years of evolution.’
    • ‘They are followed by adult males, anestrous females and immature whales of both sexes.’
    • ‘A work striking in its simplicity, Yoni Smile is likely a nod to the Hindu symbol for the female sex.’
    • ‘While there are only two sexes - male and female - there can be an unlimited number of genders.’
    1. 2.1[mass noun] The fact of belonging to either the male or female sex:
      ‘direct discrimination involves treating someone less favourably on the grounds of their sex’
      • ‘As an educated woman, Addams was constrained by the fact of her sex, and yet eager to be effective in the world.’
      • ‘The Government is considering whether to change the law to ensure the ban on couples choosing the sex of their baby can be effectively enforced.’
      • ‘It has nothing to do with the sex of a living creature.’
      • ‘Kelly Holmes has been out of the army for six years now but still she bemoans the fact that her sex precluded her from getting into the boxing ring and pummelling a few people.’
      • ‘Why the sex of the donor affects the outcome of organ transplants is not known.’
      • ‘It is virtually impossible to tell the sex of the birds, but it is statistically unlikely all eight are of the same gender, so the centre is very optimistic over breeding!’
      • ‘Mr Thompson claimed the dress code discriminated against him because of his sex and breached his human rights.’
      • ‘The penchant for short-term mating also showed effects of identity status and sex.’
      • ‘It was this direct discrimination against women, on the basis of their sex, that Emmeline Pankhurst fought to end.’
      • ‘Some attributed likeability to characteristics such as sex or nationality.’
      • ‘Despite some close friends, no one knew her true sex, and that fact was what had saved her from her mother's fate.’
      • ‘There are rare cases where the true sex of a child is confused because of poorly developed genital organs at birth.’
      • ‘A review of the literature on identifying sex from facial appearances yielded one small study from Nashville, Tennessee.’
      • ‘Unless there is a risk of a baby being born with a sex-linked condition such as haemophilia, therefore, she is against being able to choose the sex of your child.’
      • ‘When people judge the group on the basis of our sex, they're missing the point.’
      • ‘Female sex and young age are independently associated with a favourable outcome.’
      • ‘But it is precisely because the sex of a human is so intrinsic to their being that it should not be left to the whim of parental desire.’
      • ‘Therefore, most patients in this group were selected based on their female sex.’
      • ‘They already have sons, Tristan and Angus, at the village school, and know the sex of their new baby, but are keeping the knowledge to themselves.’
      • ‘Female sex was not a risk factor for any outcomes.’
    2. 2.2 The group of all members of either the male or female sex:
      ‘she was well known for her efforts to improve the social condition of her sex’
      • ‘In most species, females are the choosier sex and discriminate between several males before they choose a mate.’
      • ‘She pointed out to them that the class was unfairly divided between the sexes and that the situation would soon change.’
      • ‘Feminists might be surprised to hear it, but females are the dominant sex in most primate communities.’
      • ‘Shame on these women who don't use their power to help the weaker members of their sex.’
      • ‘Originally, people believed that morality also resided with the male sex.’
      • ‘It's a brilliant ode that can be appreciated by members of both sexes.’
      • ‘For the first time in the history of the human colony, the sexes had been segregated.’
      • ‘Elsewhere on the record, Merchant plays the role of experienced woman, dispensing advice to younger members of her sex.’
      • ‘I used to regard the male sex with deep suspicion - but the more my son teaches me about men, the more I like them.’
      • ‘But the attempts to rally the male sex under an equality banner were immediately cut down by the Government.’
      • ‘They do so also because they believe that spending time alone with members of their own sex enriches their lives.’
      • ‘He was a lovelorn twit, always chasing after some impossible girl, with more need for than understanding of the female sex.’
      • ‘I fail to see how this is incompatible with a 35 hour week and with the capabilities of the female sex.’
      • ‘But not all members of her sex empathise with Mary, says Fergusson.’
      • ‘That guy has no consideration or respect for the female sex.’
      • ‘Members of both sexes are getting heavily into debt to pay for operations on credit cards or through bank loans.’
      • ‘Watch them when they are talking to members of their own sex and you'll see what I mean.’
      • ‘She then asks men to observe all of nature and find another example of how the female sex is treated the same way.’
      • ‘Perhaps the first division of labor between the sexes was that the male became the hunter and the female the food-gatherer.’
      • ‘Is the audience for ‘Harry Potter’ divided evenly among the sexes or is it more boy-oriented?’


  • 1Determine the sex of:

    ‘each bird would need to be individually sexed’
    • ‘Animals could be sexed 1 year from birth using our enhanced feeding protocols.’
    • ‘We aged and sexed all birds captured and marked individuals with one aluminum federal band and a unique combination of three color bands.’
    • ‘Offspring were sexed at emergence and maintained in single-sex cultures.’
    • ‘I think they came over because they were more adept at sexing chickens than we were.’
    • ‘We collected pupae and sexed them by the morphology of the eighth abdominal segment.’
  • 2sex something upinformal Present something in a more interesting or lively way.

    • ‘There is little attempt to sex things up for a restless modern audience or indulge in self-conscious irony.’
    • ‘They have really gone out of their way to sex this series up.’
    • ‘‘There's a danger of treating the election as if it's boring so that you have to sex it up,’ he said, at today's official launch of the BBC's election night coverage.’
    • ‘As a result, ordinary academic books have been sexed up by mainstream publishers and heavily promoted in the mass market.’
    • ‘In his historical pastiche, Wells elects to take the past and sex it up a little.’
    • ‘His first couple of books were mysteries, and she said she liked them well enough, but by the time he started his third novel he was agitated about the lackluster sales, so he tried sexing things up.’
    • ‘Gilligan had a genuine scoop - but made the mistake of sexing it up a notch too far.’
    • ‘Apparently, they accused the Government of sexing things up.’
    • ‘Six days later He gave evidence and said it was untrue the dossier had been sexed up or that the government had pressured intelligence agencies.’
    • ‘‘The dossier was not sexed up by him or anyone else,’ said the committee.’
  • 3sex someone upinformal Arouse or attempt to arouse someone sexually.

    • ‘I can easily sleep with him, not sex him up, but just sleep, peacefully, in the same bed.’


On the difference in use between the words sex (in sense 2 above) and gender, see gender


Late Middle English (denoting the two categories, male and female): from Old French sexe or Latin sexus.