noun \ˈseks\

: the state of being male or female

: men or male animals as a group or women or female animals as a group

: physical activity in which people touch each other's bodies, kiss each other, etc. : physical activity that is related to and often includes sexual intercourse

Full Definition of SEX

:  either of the two major forms of individuals that occur in many species and that are distinguished respectively as female or male especially on the basis of their reproductive organs and structures
:  the sum of the structural, functional, and behavioral characteristics of organisms that are involved in reproduction marked by the union of gametes and that distinguish males and females
a :  sexually motivated phenomena or behavior
b :  sexual intercourse
:  genitalia

Examples of SEX

  1. The form asks for your name, age, and sex.
  2. The couple didn't know what the sex of their baby would be.
  3. How do you tell the sex of a hamster?
  4. discrimination on the basis of sex
  5. Some feel men are the more aggressive sex.
  6. All he ever thinks about is sex.
  7. Her mom talked to her about sex.
  8. She doesn't like all the sex and violence in movies.
  9. He had sex with his girlfriend.

Origin of SEX

Middle English, from Latin sexus
First Known Use: 14th century

Other Biology Terms

autochthonous, fecund, homunculus, phylogeny, substrate

Rhymes with SEX


transitive verb

Definition of SEX

:  to identify the sex of <sex newborn chicks>
a :  to increase the sexual appeal of —often used with up
b :  to arouse the sexual desires of

First Known Use of SEX



noun    (Concise Encyclopedia)

Sum of features by which a member of a plant or animal species can be placed into one of two complementary reproductive groups, male or female. In both plants and animals, sex is determined by the reproductive cells (gametes) produced by the organism. The male produces sperm cells, and the female produces egg cells. Males and females may or may not have apparent structural differences, but they always have functional, hormonal, and chromosomal differences. Patterns of behaviour, sometimes elaborate, may also distinguish the sexes in some species. See also reproductive behaviour.


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