agnostic ambiguous capricious chancy changeable controvertible dicey doubting equivocal erratic fickle hesitant hesitating incalculable indecisive indemonstrable irresolute polysemous skeptical touch-and-go unaccountable unattestable uncertain unconfirmable unconvinced undemonstrable undemonstratable undivinable unforeseeable unpersuaded unpredictable unsubstantiatable unsupportable unsure unsustainable unverifiable variable wavering whimsical