| strange(silly, foolish, fantastic, unwise, impractical) |
| tomfool(adjective, foolish) |
| undiscriminating |
| unimaginative |
| unintelligent(weak, simple, silly, foolish, thoughtless) |
| unsophisticated |
| unworkable(silly, foolish, fantastic, unwise, impractical) |
| unworldly |
| wacky(weak, simple, silly, foolish, thoughtless) |
| weak(simple, silly, foolish, thoughtless, unwise) |
| weird(silly, foolish, fantastic, unwise, impractical) |
| zany(weak, simple, silly, foolish, thoughtless) |
| ape(silly, foolish, unwise) |
| backward(impulsive, impractical, half-baked, doomed, unplanned) |
| barmy(silly, foolish, unwise) |
| bats in the belfry(expression, idiom, silly, foolish, unwise) |
| batty(silly, foolish, impulsive, unwise, impractical) |
| berserk(silly, foolish, unwise) |
| beyond reason(expression, foolish, fantastic, unrealistic) |
| birdbrained(impulsive, impractical, half-baked, doomed, unplanned) |