adult

a person old enough to be treated by the law as no longer a child

An animal that is full-grown.

Fully grown.

Intended for or restricted to adults rather than children due to size, maturity, knowledge level, judgement, etc.

Containing situations or discussions intended primarily for adults, such as serious crime, illicit drug use, extramarital affairs, etc.

Containing alcohol, intended for consumption only by adults.

Containing marijuana, intended for consumption only by adults.

Containing excessive vulgar or profane speech, text or images, intended only for adults.

Intended for, or restricted to, those who are not young children.

(euphemistic) Containing material of an explicit sexual nature; pornographic.

(slang) To behave like an adult.

(nonstandard, rare) To (cause to) be or become an adult.