| asinine(adjective, weak, simple, silly, foolish) |
| balmy(adjective, knowledge, slang, ability, foolish) |
| batty(adjective, light, silly, stupid, mad) |
| cuckoo(adjective, silly, foolish, mad, insane) |
| nuts(adjective, slang, crazy, mad) |
| preposterous(adjective, knowledge, ability, foolish, stupid) |
| ridiculous(adjective, light, foolish, stupid, crazy) |
| screwy(adjective, light, silly, crazy, mad) |
| bonkers(adjective, slang, crazy, mad) |
| cockeyed(adjective, knowledge, slang, ability, informal) |
| harebrained(adjective, weak, simple, knowledge, ability) |
| irrational(adjective, weak, foolish, stupid, crazy) |
| kooky(adjective, weak, silly, foolish, crazy) |
| ludicrous(adjective, light, simple, foolish, stupid) |
| barmy(adjective, silly, foolish, mad, insane) |
| dopey(noun, adjective, knowledge, slang, ability) |
| potty(adjective, silly, foolish, mad, insane) |
| senseless(adjective, weak, simple, strange, silly) |
| witless(adjective, weak, simple, silly, foolish) |
| zany(adjective, weak, simple, knowledge, ability) |