| nutty as fruitcake(expression, idiom, silly, foolish) |
| of unsound mind(expression, adjective, idiom, silly, foolish) |
| round the bend(expression, idiom, silly, foolish) |
| screw loose(expression, silly, foolish, insane) |
| unhinged(adjective, silly, foolish, insane) |
| ape(silly, foolish, insane, unwise) |
| berserk(adjective, silly, foolish, insane) |
| cock-eyed(adjective, slang, crazy) |
| cockamamie(adjective, slang, crazy) |
| delirious(silly, foolish, insane, unwise) |
| dingy(silly, foolish, insane, unwise) |
| erratic(silly, foolish, insane, unwise) |
| in a tizzy(adjective, slang, crazy) |
| locoed(adjective, slang, crazy) |
| maniacal(silly, foolish, crazy, insane) |
| meshugah(adjective, slang, crazy) |
| moonstruck(silly, foolish, insane, unwise) |
| narly(adjective, slang, crazy) |
| pixilated(adjective, slang, crazy) |
| psycho(silly, foolish, insane, unwise) |