pumpkin head

a slow or dim-witted person; dunce.

Origin of pumpkin head

An Americanism dating back to 1775–85

pump·kin-head·ed, adjective

pumped storage, pumper, pumpernickel, pumping, pumpkin, pumpkin head, pumpking, pumpkinseed, pumpman, pun, puna

And his father was before him, and Gigetto will be after him, with his pumpkin-head.

Casa Braccio, Volumes 1 and 2 (of 2) |F. Marion Crawford
Somebody has been told that somebody else heard some other pumpkin-head say so.

A Siren |Thomas Adolphus Trollope
Jack was wearing a newly made Pumpkin-head and the Scarecrow had recently been stuffed with fresh straw.

Glinda of Oz |L. Frank Baum
Pumpkin-head would have burst, if I'd let out I didn't know what part of the jolly old world my governor used to run.

Sinister Street, vol. 2 |Compton Mackenzie

Ah, pumpkin-head, why did you not think to make all that profit?

The Purple Land |W. H. Hudson