| Dolt |
| Dope |
| Fool |
| Boob |
| Dummy |
| Ninny |
| Chump |
| Dunce |
| Stupe |
| Dimwit |
| Doofus |
| Nitwit |
| Airhead |
| Bonehead |
| Dumbbell |
| Meathead |
| Blockhead |
| Easy mark |
| Ignoramus |
| Lamebrain |
| Birdbrain |
| Dunderhead |
| Nincompoop |
| Chowderhead |
| Chucklehead |
| Featherbrain |
| Gullible sort |
| Gullible type |
| Foolish fellow |
| Foolish person |
| Easily duped sort |
| Not the brightest bulb on the tree |