| insane(adjective, simple, silly, foolish, crazy) |
| deranged(adjective, simple, silly, foolish) |
| unbalanced(adjective, silly, foolish, crazy) |
| nuts(adjective, slang, silly, foolish, crazy) |
| lunatic(adjective, simple, silly, foolish) |
| daft(adjective, informal, silly, foolish, stupid) |
| batty(adjective, silly, foolish, stupid, crazy) |
| bonkers(adjective, simple, silly, foolish) |
| psycho(noun, adjective, slang, silly) |
| barmy(adjective, silly, foolish, crazy) |
| demented(adjective, simple, silly, foolish) |
| nutty(adjective, simple, silly, foolish) |
| screwy(adjective, silly, foolish, crazy) |
| unhinged(adjective, simple, silly, foolish) |
| crazed(adjective, silly, foolish, stupid, crazy) |
| of unsound mind(expression, adjective, idiom, silly) |
| cracked(adjective, simple, silly, foolish) |
| cuckoo(noun, adjective, slang, silly) |
| touched(adjective, simple, silly, foolish) |
| out to lunch(expression, adjective, idiom, silly) |