| kooky(adjective, wild, silly, foolish, crazy) |
| of unsound mind(expression, adjective, idiom, silly) |
| screwy(adjective, slang, silly, foolish, crazy) |
| fruity(adjective, slang, silly, foolish) |
| mental(adjective, simple, silly, foolish) |
| moonstruck(adjective, silly, foolish, stupid) |
| psychotic(adjective, silly, foolish, stupid, crazy) |
| round the bend(expression, adjective, idiom, silly, foolish) |
| daffy(adjective, simple, informal, silly, foolish) |
| out to lunch(expression, adjective, idiom, silly) |
| potty(adjective, wild, silly, foolish, stupid) |
| psycho(silly, foolish, crazy, insane) |
| irrational(adjective, wrong, wild, silly, foolish) |
| maniacal(adjective, silly, crazy, insane) |
| silly(adjective, wild, foolish, stupid, crazy) |
| idiotic(adjective, wild, silly, foolish, stupid) |
| bats in the belfry(expression, idiom, silly, foolish) |
| berserk(adjective, silly, foolish, crazy) |
| cockamamie(adjective, silly, foolish, crazy) |
| delirious(adjective, silly, foolish, crazy) |