| thoughtless(adjective, careless, indifferent, foolish, stupid) |
| unintelligent(adjective, dull, simple, slight, silly) |
| dotty(adjective, foolish) |
| illogical(adjective, simple, poor, silly, stupid) |
| imbecile(adjective, dull, simple, silly, foolish) |
| irrational(adjective, careless, wild, silly, foolish) |
| nutty(adjective, wild, silly, foolish, stupid) |
| unreasonable(adjective, simple, poor, careless, silly) |
| unwise(adjective, simple, careless, wild, silly) |
| vapid(adjective, dull, weak, soft, slight) |
| dim-witted(adjective, foolish, stupid) |
| ignorant(adjective, simple, slight, silly, foolish) |
| inept(poor, careless, foolish, stupid, rash) |
| nuts(adjective, simple, silly, foolish, unsound) |
| outlandish(adjective, silly, foolish, absurd, unwise) |
| puerile(adjective, dull, silly, foolish, stupid) |
| scatterbrained |
| unthinking(adjective, dull, slight, careless, indifferent) |
| wacky(adjective, wild, silly, foolish, stupid) |
| witless(adjective, dull, simple, slow, careless) |