doubtful

modif.

1. Ambiguous

   in doubt, questionable, problematic, vague, indistinct, unclear, indefinite, undetermined, unresolved, open to doubt, in question, equivocal, unsure, indeterminate, under examination, debatable, theoretical, up in the air*, iffy*, yes and no*, out of focus*; see also obscure 1, questionable 1, uncertain 2.

2. Uncertain in mind

   dubious, doubting, questioning, skeptical, undecided, unsure, wavering, hesitating, ambivalent, undetermined, uncertain, unsettled, confused, disturbed, lost, puzzled, disconcerted, perplexed, discomposed, flustered, flurried, baffled, hesitant, distracted, faltering, unresolved, in a quandary, of two minds, unable to make up one's mind, vacillating, indecisive, irresolute, agnostic, like a doubting Thomas, troubled with doubt, of little faith, faithless, distrustful, incredulous, cynical, not knowing what's what, having no idea, in a dilemma, under a spell*, in the clouds*, up a tree*, in a haze*, not able to make head or tail of*, from Missouri*, going around in circles*, out of one's bearings*, up in the air*, wishy-washy*; see also suspicious 1.

3. Of questionable character

   dubious, sneaky, disreputable, shady*; see questionable 2, suspicious 2.

doubtful implies strong uncertainty as to the probability, value, honesty, validity, etc. of something a doubtful remedy; dubious is less strong, suggesting merely vague suspicion or hesitancy dubious about the future; questionable strictly suggests only that there is some reason for doubt, but it is often used as a euphemism to imply strong suspicion, almost amounting to certainty, of immorality, dishonesty, etc. a questionable reputation; problematic implies only uncertainty with no suggestion of a moral question a problematic success