Synonyms of adultnext
1
: fully developed and mature : grown-up
an adult lion
2
: of, relating to, intended for, or befitting adults
an adult approach to a problem
3
: dealing in or with explicitly sexual material
adult bookstores
adult movies
adulthood noun
adultly
ə-ˈdəlt-lē How to pronounce adult (audio)
ˈa-ˌdəlt-
adverb
adultness
ə-ˈdəlt-nəs How to pronounce adult (audio)
ˈa-ˌdəlt-
noun

Examples of adult in a Sentence

preparing children for adult life We need to approach this in an adult way.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Males dusky sharks can grow up to 14 feet, which is about the size of a sub-adult white shark, according to Chapman. Julia Jacobo, ABC News, 1 June 2026 It is estimated that, based on measures of blood glucose, lipids, and other parameters, less than 12% of the adult American population can even be said to metabolically healthy. Christopher Duggan, STAT, 27 Mar. 2026 For many readers and critics, the perception was that Mansfield was almost writing children’s fiction, since most of her stories are deceptively easy to read, although her themes are entirely adult in both form and content. Literary Hub, 17 Dec. 2025 Justin Vernon’s midwestern charm and pliable falsetto has always endeared him to indie-rock dads raised on Michael McDonald, but starting a family himself between Bon Iver projects turned this year’s Sable, Fable into a deep examination of the fatherly adult contemporary figure in popular music. Craig Jenkins, Vulture, 2 Dec. 2025 See All Example Sentences for adult

Word History

Etymology

borrowed from French & Latin; French adulte, going back to Middle French, borrowed from Latin adultus, from past participle of adolēscere, adulēscere "to become mature, grow up," from ad- ad- + alēscere "to be nourished, grow up," probably inchoative derivative of *alēre "to grow," stative derivative of alere "to nurse, feed, nourish" — more at old entry 1

First Known Use

1531, in the meaning defined at sense 1

Time Traveler
The first known use of adult was in 1531

Cite this Entry

“Adult.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/adult. Accessed 10 Jun. 2026.

Kids Definition

adult

1 of 2 adjective
1
: fully developed and mature
2
: of, relating to, or characteristic of adults
adulthood noun
adultness
ə-ˈdəlt-nəs How to pronounce adult (audio)
ˈad-ˌəlt-
noun

adult

2 of 2 noun
: a fully grown person, animal, or plant
adultlike adjective
Etymology

from Latin adultus "having grown up," from adolescere "to grow up" — related to adolescence

Medical Definition

adult

1 of 2 adjective
: fully developed and mature

adult

2 of 2 noun
1
: one that has arrived at full development or maturity especially in size, strength, or intellectual capacity
2
: a human male or female after a specific age (as 18 or 21)

Legal Definition

adult

noun
: a person who has reached an age specified by law compare child, infant, minor

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