| improbable(shaky, unlikely, unpromising) |
| incredible(adjective, thin, doubtful, dubious, suspicious) |
| insecure(adjective, uncertain, shaky, unclear, unlikely) |
| open(adjective, uncertain, doubtful, unsettled, shaky) |
| open to question(expression, adjective, idiom, dubious, suspect) |
| queer(adjective, dubious, suspect, shady) |
| ridiculous(adjective, thin, doubtful, dubious, suspicious) |
| shady(adjective, uncertain, doubtful, unsettled, shaky) |
| shaky(adjective, thin, unusual, uncertain, doubtful) |
| speculative(uncertain, shaky, unclear, unlikely, questionable) |
| thick(adjective, thin, doubtful, dubious, suspicious) |
| thin(adjective, doubtful, dubious, suspicious) |
| unbelievable(adjective, thin, doubtful, dubious, suspicious) |
| uneasy(uncertain, shaky, unclear, unlikely, questionable) |
| unpromising(shaky, unlikely) |
| unsure(adjective, uncertain, doubtful, unsettled, dubious) |
| absurd |
| at issue |
| beyond belief |
| borderline(uncertain, doubtful, shaky, dubious, unclear) |