| loopy(adjective, knowledge, ability, informal, foolish) |
| lunatic(adjective, weak, simple, knowledge, ability) |
| mindless(adjective, careless, wild, silly, foolish) |
| moronic(adjective, weak, simple, knowledge, ability) |
| potty(adjective, wild, silly, foolish, stupid) |
| puerile(silly, foolish, stupid, fantastic, trivial) |
| screwball(silly, foolish, unwise) |
| softheaded(adjective, knowledge, ability) |
| unbalanced(silly, foolish, unreliable, changeable, unwise) |
| unconsidered(adjective, rash) |
| unreasonable(weak, simple, silly, foolish, stupid) |
| unwise(weak, simple, silly, foolish, stupid) |
| venturesome(adjective, careless, wild, bold, thoughtless) |
| weak-minded |
| whimsical(excited, unreliable, changeable, fearful, fickle) |
| adventuresome(adjective, careless, wild, bold, thoughtless) |
| airy |
| arbitrary |
| astonishing(extraordinary, amazing, dubious, incredible) |
| barmy(adjective, careless, silly, foolish, stupid) |