Blockhead, 4 letters
Breathink orkan, 4 letters
Dolt, 4 letters
Dullard, 4 letters
Idiot, 4 letters
Muttonhead, 4 letters
Numskull, 4 letters
Bozo, 8 letters
Dolt, 8 letters
These words are used to express a low opinion of someone's intelligence, 8 letters
Blockheads, 5 letters
Boobs, 5 letters
Dullards, 5 letters