• Airheads
• Birdbrains
• Blockheads
• Boneheads
• Chowderheads
• Clods
• Dimbulbs
• Dimwits
• Dull chaps.
• Dunces
• Dunderheads
• Featherbrains
• Foolish fellows
• Fools
• Half-wits
• Idiots
• Ignorant fools
• Knuckleheads
• Lamebrains
• Lunkheads
• Meatheads
• Morons
• Noodleheads
• Not exactly Einsteins
• Not the sharpest knives in the drawer
• Numskulls.
• Oafs
• Schmoes
• Simpletons
• Yo-yos