doubtful

/ˈdau̇t-fəl/

adjective

  1. lacking a definite opinion, conviction, or determination

  2. uncertain in outcome : undecided

  3. marked by qualities that raise doubts about worth, honesty, or validity

They were doubtful about the advantages of the new system.

The outcome of the election remains doubtful.

doubtful dubious problematic questionable mean not affording assurance of the worth, soundness, or certainty of something. doubtful implies little more than a lack of conviction or certainty. dubious stresses suspicion, mistrust, or hesitation.