Definition: in a manner construed as childish or relating to children
Part of Speech: Adjective
Synonym(s): childlike, simple
Antonym(s): mature, grown-up
1. Hopefully this will be the boy’s first and only appearance in juvenile court.
2. Despite his age, Ted behaves in a juvenile manner when he gets around women.
3. Your juvenile temper tantrum isn’t going to help you get your way this time.