questionable

Synonyms: ambiguous apocryphal arguable contingent controversial controvertible cryptic debatable disputable dubious dubitable enigmatic equivocal fishy hard to believe hypothetical iffy indecisive indefinite indeterminate moot mysterious obscure occult open to doubt open to question oracular paradoxical problematic problematical provisional shady suspect suspicious unconfirmed undefined under advisement under examination unproven unreliable unsettled vague

Antonyms: certain definite indisputable proven sure undoubted unquestionable