(US, slang) Engaging in activities typically associated with adulthood. / (nonstandard) Adultery.

present participle of adult

plural of young adult

plural of appropriate adult

plural of older adult

Content, such as pornography or violence, that is not generally thought to be appropriate for viewing by children.

(euphemistic) a pornographic film

A person who has achieved the age of majority but whose character and personality are still developing as they gain experience.

plural of adult movie

(euphemistic) An old person. / Used other than figuratively or idiomatically: see older, adult.