Definitely no genius, 4 letters
Dumb & Dumber type, 4 letters
Dunce-cap candidate, 4 letters
Hardly a Mensa candidate, 4 letters
He's not a Mensa candidate, 4 letters
No rocket scientist, 4 letters
One who is not very bright, 4 letters
One who isn't quick, 4 letters
One who isn't swift, 4 letters
Unlikely Mensa candidate, 4 letters
A person who is not very bright, 4 letters
Fastener on a pilgrim's dunce cap?, 10 letters
Not exactly Einsteins, 5 letters