idiot, fool, loser, someone who acts childish, immature.
"stop being an arbutus" he shouted to the young man who was throwing coins at the young girls.
A tree/human in an episode of 'Disney Princess - Aladin' who at first seems evil, because he doesn't understand how humans need friends, but at the end, he was nice.
Arbutus: Jasmine... I think I understand.
Jasmine: Y..y..you do?