# adult

/ˈædəɫt/ (US) · /ˈædʌlt/ (UK)

Source: https://englishreference.com/word/adult
Updated: 2026-06-19

## Senses

### 1. a grown person

noun · CEFR A2

a person who is fully grown or has reached the legal age to be responsible for themselves.

For teachers: a human being who has reached the legal age of majority or is physically and mentally mature.

- The museum ticket is ten dollars for an adult and five dollars for a child.
- In many jurisdictions, a person is legally considered an adult at eighteen, granting them the right to vote and enter into binding contracts.

### 2. mature animal

noun · CEFR B2 · Technical

an animal or plant that is fully grown and can produce young.

For teachers: an organism that has reached its final stage of development and is capable of reproduction.

- The adult butterfly looks very different from the caterpillar it used to be.
- The researchers monitored the migration patterns of adult salmon as they returned to their natal streams to spawn.

### 3. fully grown

adjective · CEFR A2

having reached full size or maturity.

For teachers: having attained full physical growth or development.

- An adult male elephant can weigh over six thousand kilograms.
- The sanctuary provides a safe environment for adult tigers that were rescued from illegal private collections.

### 4. age-restricted

adjective · CEFR B1

meant only for adults, often because it contains violence or sexual content.

For teachers: intended for or restricted to adults, typically due to mature themes, sexual content, or graphic violence.

- The movie was rated R, meaning it was for an adult audience only.
- The bookstore has a separate section for adult fiction that explores complex political and social themes unsuitable for younger readers.

### 5. to act responsibly

verb · CEFR C1 · Informal · Slang

to do the boring but necessary things that grown-ups have to do, like paying bills.

For teachers: to behave in a manner characteristic of a responsible adult, especially by performing mundane or difficult tasks.

- I am not ready to adult today; I just want to stay in bed.
- After a long week of adulting—paying taxes, fixing the car, and grocery shopping—she spent the entire Sunday playing video games.

Usage: Often used in the continuous form 'adulting'.

Teaching tip: This is a modern, humorous term used by young adults to describe the struggle of daily responsibilities.

## Examples

- The museum ticket is cheaper for children than for adults.
- The hotel pool is reserved for adults only during the evening hours to ensure a quiet environment for guests.
- Sociologists often debate whether the transition to being an adult is defined more by biological maturity or by the financial independence required to support a household.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.