| barmy(adjective, silly, foolish, trivial) |
| cracked(adjective, wild, silly, foolish, stupid) |
| flaky(adjective, wild, silly, foolish, stupid) |
| zany(adjective, weak, simple, knowledge, ability) |
| bats in the belfry(expression, idiom, silly, foolish) |
| bonkers(adjective, simple, silly, foolish, crazy) |
| crazed(adjective, wild, silly, foolish, stupid) |
| deranged(adjective, wild, silly, foolish, stupid) |
| flipped out(expression, silly, foolish, crazy) |
| freaked out(expression, silly, foolish, crazy) |
| kooky(weak, simple, silly, foolish, crazy) |
| mad as a March hare(expression, idiom, silly, foolish) |
| mad as a hatter(expression, idiom, silly, foolish) |
| maniacal(adjective, mind, think, silly, crazy) |
| mentally strange(expression, silly, foolish, insane) |
| moonstruck(adjective, silly, foolish, stupid) |
| nutty as fruitcake(expression, idiom, silly, foolish) |
| of unsound mind(expression, idiom, silly, stupid) |
| out to lunch(expression, idiom, dull, silly) |
| potty(adjective, wild, silly, foolish, stupid) |