smurfbrain

smurfbrain

A foolish, unintelligent, or dim-witted person. An allusion to the small size of the fictional cartoon characters known as Smurfs. Her new boyfriend certainly is attractive, but he's a bit of a smurfbrain, don't you think? Sorry, I've been a total smurfbrain all day. I didn't get a whole lot of sleep last night.
Farlex Dictionary of Idioms.

smurfbrain

(ˈsmɚfbren)
n. a simple-minded person. (A smurf is an innocent little cartoon character.) You can be such a smurfbrain!
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • airbrain
  • airhead
  • couldn't find (one's) way out of a paper bag
  • out of a paper bag
  • (one's) way out of a paper bag
  • (one's) way out of a wet paper bag
  • pumpkin head
  • airheaded
  • not the sharpest tool in the shed
  • not the sharpest pencil in the cup