questionable

/ˈkwes-chə-nə-bəl/

adjective

  1. inviting inquiry

  2. liable to judicial inquiry or action

  3. affording reason for being doubted, questioned, or challenged : not certain or exact : problematic

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.