gumbyhead

gumbyhead

slang Someone whose actions are typically silly or stupid. Geez, he keeps pulling on a door that's clearly marked "push"—what a gumbyhead.
Farlex Dictionary of Idioms.

gumbyhead

(ˈgəmbihɛd)
n. someone who does stupid things like the character, Gumby. Don’t be a gumbyhead. Don’t drink and drive.
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • dinghead
  • dipwad
  • blockhead
  • dimwit
  • dingleberry
  • dingus
  • dingy
  • dingbat
  • doofus
  • ding-a-ling