dubious β doubtful; marked by or occasioning doubt: a dubious reply.
questionable β of doubtful propriety, honesty, morality, respectability, etc.: questionable activities; in questionable taste.
arguable β If you say that it is arguable that something is true, you believe that it can be supported by evidence and that many people would agree with it.
argumentative β Someone who is argumentative is always ready to disagree or start quarrelling with other people.
contended β Simple past tense and past participle of contend.
contestable β a race, conflict, or other competition between rivals, as for a prize.
controvertible β to argue against; dispute; deny; oppose.
uneasy β not easy in body or mind; uncomfortable; restless; disturbed; perturbed.
unsettled β not settled; not fixed or stable; without established order; unorganized; disorganized: an unsettled social order; still unsettled in their new home.
unstable β not stable; not firm or firmly fixed; unsteady.
unsure β not certain or confident: He arrived at the party unsure of his welcome.
ambiguous β If you describe something as ambiguous, you mean that it is unclear or confusing because it can be understood in more than one way.
borderline β The borderline between two different or opposite things is the division between them.
chancy β Something that is chancy involves a lot of risk or uncertainty.
clouded β of or relating to cloud computing: cloud software; cloud servers.
contingent β A contingent of police, soldiers, or military vehicles is a group of them.
disreputable β not reputable; having a bad reputation: a disreputable barroom.
far-fetched β improbable; not naturally pertinent; being only remotely connected; forced; strained: He brought in a far-fetched example in an effort to prove his point.
fat chance β having too much flabby tissue; corpulent; obese: a fat person.
fishy β like a fish in shape, smell, taste, or the like.
hazardous β full of risk; perilous; risky: a hazardous journey.
iffy β full of unresolved points or questions: an iffy situation.
impugnable β to challenge as false (another's statements, motives, etc.); cast doubt upon.
inconclusive β not conclusive; not resolving fully all doubts or questions: inconclusive evidence.
indefinite β not definite; without fixed or specified limit; unlimited: an indefinite number.
indeterminate β not determinate; not precisely fixed in extent; indefinite; uncertain.