| dim-witted |
| doltish(dull, silly, foolish, stupid, unintelligent) |
| dumb(dull, silly, foolish, stupid, unintelligent) |
| foolish(dull, silly, stupid, unintelligent, witless) |
| half-witted(dull, silly, foolish, stupid, unintelligent) |
| heavy |
| imbecilic(dull, silly, foolish, stupid, unintelligent) |
| inane(dull, silly, foolish, stupid, unintelligent) |
| loser(dull, unintelligent, witless, ill-starred, voodooed) |
| meaningless(dull, silly, foolish, stupid, unintelligent) |
| mindless(dull, silly, foolish, stupid, unintelligent) |
| moronic(dull, silly, foolish, stupid, unintelligent) |
| out to lunch(expression, idiom, dull, unintelligent, witless) |
| pointless(dull, silly, foolish, stupid, unintelligent) |
| senseless(dull, silly, foolish, stupid, unintelligent) |
| simple(dull, silly, foolish, stupid, unintelligent) |
| simpleminded(dull, silly, foolish, stupid, unintelligent) |
| thickheaded |
| unthinking(dull, silly, foolish, stupid, unintelligent) |
| witless(dull, silly, foolish, stupid, unintelligent) |