| cuckoo(adjective, silly, foolish, crazy, mad) |
| fanciful(adjective, happy, informal, perfect, unusual) |
| flamboyant(adjective, informal, extravagant, loud, showy) |
| foolish(adjective, wrong, wild, silly, stupid) |
| gaga(adjective, careless, lively, unstable, unreasonable) |
| haywire(adjective, eccentric) |
| idiotic(adjective, wild, silly, foolish, stupid) |
| nuts(adjective, simple, silly, foolish, crazy) |
| potty(adjective, silly, foolish, mad, insane) |
| round the bend(expression, idiom, silly, foolish, mad) |
| senseless(adjective, wrong, wild, silly, foolish) |
| strange(adjective, unusual, wild, foolish, crazy) |
| unreasonable(adjective, wrong, careless, silly, foolish) |
| aberrant(adjective, informal, unusual, wild, usual) |
| anomalous(extraordinary, unusual, wild, strange, crazy) |
| arbitrary(unusual, careless, unstable, unreasonable, irregular) |
| asinine(adjective, simple, silly, foolish, stupid) |
| bananas |
| bats |
| bats in the belfry(expression, idiom, silly, foolish, mad) |