grown-up
US /ˈɡroʊn.ʌp/
UK /ˈɡroʊn.ʌp/

1.
adulte, grande personne
a fully developed person; an adult
:
•
When you're a grown-up, you can make your own decisions.
Quand tu seras un adulte, tu pourras prendre tes propres décisions.
•
The children were told to act like grown-ups.
On a dit aux enfants de se comporter comme des adultes.