Meaning of dumbo

dum•bo

Pronunciation: (dum'bō), [key]
— n., pl. adj. -bos,
—n.
  1. a stupid person: a class full of dumbos.
—adj.
  1. stupid or foolish: What a dumbo idea!
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.