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

SEX- Defined for Kids


noun \ˈseks\

Definition of SEX for Kids

:  either of two divisions into which many living things can be divided according to their roles in reproduction and which consist of males or females
:  the state of being male or female <The form asks for your name, age, and sex.>
:  sexual activity
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