| mindless(careless, silly, stupid, unthinking, unintelligent) |
| numbskull(adjective, dull, simple, limited) |
| oafish |
| opaque |
| open to doubt(expression, idiom, extraordinary, amazing, dubious) |
| outlandish(extraordinary, amazing, incredible) |
| past belief(expression, extraordinary, amazing, dubious, astonishing) |
| phony(extraordinary, amazing, incredible) |
| preposterous(extraordinary, amazing, incredible) |
| puerile(careless, silly, stupid, unthinking, unintelligent) |
| questionable(extraordinary, amazing, incredible) |
| reaching(extraordinary, amazing, dubious, astonishing, incredible) |
| retardo(adjective, dull, simple, limited) |
| scatterbrained(extraordinary, amazing, dubious, astonishing, incredible) |
| screwy(extraordinary, amazing, dubious, astonishing, incredible) |
| senseless(careless, stupid, unthinking, obtuse, unperceptive) |
| silly(careless, stupid, unthinking, unintelligent, unaware) |
| sottish |
| staggering(extraordinary, amazing, incredible) |
| subnormal(adjective, dull, simple, limited) |