Meaning of “adult” in the English Dictionary

"adult" in British English

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adultnoun [ C ]

uk /ˈæd.ʌlt/ /əˈdʌlt/ us /ˈæd.ʌlt/ /əˈdʌlt/

A1 a person or animal that has grown to full size and strength:

An adult under English law is someone over 18 years old.
Adults pay an admission charge but children get in free.

More examples

  • The school rules state that no child shall be allowed out of the school during the day, unless accompanied by an adult.
  • The magazine is aimed at teenagers and young adults.
  • There will be two adults travelling, plus three children.
  • Let's stay calm and try to behave like responsible adults.
  • If you think of these children growing into adults who enjoy and appreciate classical music, then that repays our effort.


uk /ˈæd.ʌlt/ /əˈdʌlt/ us /ˈæd.ʌlt/ /əˈdʌlt/

(Definition of “adult” from the Cambridge Advanced Learner’s Dictionary & Thesaurus © Cambridge University Press)

"adult" in American English

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us /əˈdʌlt, ˈæd·ʌlt/

grown to full size and strength:

More than half of adult Americans are considered overweight.

Adult also means suitable for grown people and not children:

It’s a kids’ show, but they sneak in some adult humor.

Adult movies, magazines, shows, and books include content that is intended for adults only.

noun [ C ] us /əˈdʌlt, ˈæd·ʌlt/

We invited only adults to the wedding.
noun [ U ] us /əˈdʌltˌhʊd/

When she reached adulthood, she moved away.

(Definition of “adult” from the Cambridge Academic Content Dictionary © Cambridge University Press)