| astonishing(extraordinary, amazing, dubious, incredible) |
| beyond belief(expression, extraordinary, amazing, incredible) |
| cockamamie(extraordinary, amazing, dubious, astonishing, incredible) |
| cockeyed(extraordinary, amazing, dubious, astonishing, incredible) |
| doubtful(extraordinary, unreasonable, amazing, dubious, astonishing) |
| dubious(extraordinary, unreasonable, amazing, astonishing, unlikely) |
| far-fetched(extraordinary, amazing, unlikely, unbelievable, incredible) |
| fishy(extraordinary, unreasonable, amazing, dubious, unlikely) |
| flaky(extraordinary, amazing, dubious, astonishing, incredible) |
| flimsy(extraordinary, unreasonable, amazing, dubious, unlikely) |
| full of holes(expression, idiom, extraordinary, unreasonable, dubious) |
| harebrained(extraordinary, amazing, dubious, astonishing, incredible) |
| implausible(adjective, extraordinary, amazing, likely, unlikely) |
| impossible(extraordinary, unreasonable, amazing, dubious, unlikely) |
| improbable(extraordinary, unreasonable, amazing, dubious, unlikely) |
| incogitable(extraordinary, amazing, dubious, astonishing, incredible) |
| inconceivable(extraordinary, unreasonable, amazing, dubious, unlikely) |
| incredible(extraordinary, unreasonable, amazing, dubious, unlikely) |
| kooky(extraordinary, amazing, dubious, astonishing, incredible) |
| lamebrained(extraordinary, amazing, dubious, astonishing, incredible) |