Word forms: plural grown-upslanguage note: The spelling grownup is also used. The syllable up is not stressed when it is a noun.1. countable nounA grown-up is an adult; used by or to children.
Jan was almost a grown-up.
Tell children to tell a grown-up if they're being bullied.
Synonyms: adult, man, woman More Synonyms of grown-up
2. adjectiveSomeone who is grown-up is physically and mentally mature and no longer depends on their parents or another adult.
I have grown-up children who're doing well.
3. adjective [usually verb-link ADJECTIVE]If you say that someone is grown-up, you mean that they behave in an adult way, often when they are in fact still a child.
She's very grown-up.
4. adjectiveGrown-up things seem suitable for or typical of adults.
[informal] Her songs tackle grown-up subjects.
She talked in a grown-up manner.
More Synonyms of grown-up