| doubtful(unlikely, implausible) |
| dubious(doubtful, unlikely, implausible) |
| far-fetched(doubtful, unlikely, implausible) |
| flimsy(doubtful, unlikely, implausible) |
| hundred-to-one(doubtful, unlikely, implausible) |
| iffy(doubtful, unlikely, implausible) |
| improbable(adjective, doubtful, likely, unlikely, implausible) |
| 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) |
| unbelievable(doubtful, unlikely, implausible) |
| uncertain(doubtful, unlikely, implausible) |
| unconvincing(doubtful, unlikely, implausible) |
| unheard of(expression, doubtful, unlikely, implausible) |
| unsubstantial(doubtful, unlikely, implausible) |
| weak(doubtful, unlikely, implausible) |
| fanciful(doubtful, unlikely, implausible) |
| implausible(doubtful, unlikely) |