| doubtful(unlikely, implausible) |
| dubious(doubtful, unlikely, implausible) |
| far-fetched(doubtful, unlikely, implausible) |
| flimsy(doubtful, unlikely, implausible) |
| fling(chance, risk, possibility, luck, accident) |
| go(chance, risk, possibility, luck, accident) |
| hazard(noun, chance, luck, accident) |
| iffy(doubtful, unlikely, implausible) |
| impracticable(unreasonable, useless, doubtful, absurd, unlikely) |
| improbable(adjective, doubtful, likely, unlikely, implausible) |
| inconceivable(unreasonable, useless, doubtful, absurd, hopeless) |
| long shot(expression, chance, risk, possibility, luck) |
| not expected(expression, doubtful, unlikely, implausible) |
| not likely(expression, doubtful, unlikely, implausible) |
| outside chance(expression, doubtful, unlikely, implausible) |
| questionable(doubtful, unlikely, implausible) |
| slim(doubtful, unlikely, implausible) |
| slim and none(expression, idiom, doubtful, unlikely, implausible) |
| unachievable |
| unbelievable(doubtful, unlikely, implausible) |