| treacherous(adjective, delicate, uncertain, unsound, insecure) |
| tricky(adjective, delicate, uncertain, sensitive, unstable) |
| uncertain(adjective, delicate, sensitive, unstable, doubtful) |
| unfixed(adjective, doubtful, vague, hesitant, changeable) |
| unforeseeable(adjective, doubtful, vague, hesitant, changeable) |
| unhealthy(adjective, delicate, uncertain, sensitive, unstable) |
| unpredictable(adjective, doubtful, vague, hesitant, changeable) |
| unreliable(adjective, delicate, uncertain, unstable, doubtful) |
| unresolved(adjective, doubtful, vague, hesitant, changeable) |
| unsafe(adjective, delicate, uncertain, sensitive, unstable) |
| unsettled(adjective, delicate, uncertain, unstable, doubtful) |
| unsound(adjective, delicate, uncertain, sensitive, unstable) |
| unstable(adjective, delicate, uncertain, doubtful, unsettled) |
| unsteady(adjective, delicate, uncertain, unstable, doubtful) |
| unsure(adjective, delicate, uncertain, unstable, doubtful) |
| up for grabs(expression, adjective, idiom, doubtful, vague) |
| up in the air(adjective, doubtful, vague, hesitant, changeable) |
| vacillating(adjective, doubtful, vague, hesitant, changeable) |
| variable(adjective, doubtful, vague, hesitant, changeable) |
| venturesome(adjective, delicate, uncertain, unsound, dangerous) |