Not settled in opinion; undetermined; wavering; hesitating in belief; also used, metaphorically, of the body when its action is affected by such a state of mind; as, we are doubtful of a fact, or of the propriety of a measure.
- Subject to or causing doubt: a doubtful claim; doubtful prospects.
- Experiencing or showing doubt: Doubtful that the cord would hold, we strengthened it.
- Of uncertain outcome; undecided.
- Raising doubts as to legitimacy, honesty, or respectability; suspicious: the candidate's doubtful past. See Usage Note at doubt.