grown-up
nounUK /ˈɡrəʊnʌp/
US /ˈɡroʊnʌp/
A grown-up is an adult person.
My teacher is a grown-up who helps us learn.
SYNONYMS
OTHER MEANINGS
2. Suitable for or typical of adults rather than children.
They had a grown-up conversation about money.
3. Having finished growing; fully developed.
The puppy is now a grown-up dog.
4. Behaving in a mature, responsible way.
She was very grown-up about losing the game.