'Doubtful' definitions:

Definition of 'doubtful'

(from WordNet)
adjective
Open to doubt or suspicion; "the candidate's doubtful past"; "he has a dubious record indeed"; "what one found uncertain the other found dubious or downright false"; "it was more than dubitable whether the friend was as influential as she thought"- Karen Horney [syn: doubtful, dubious, dubitable, in question(p)]
adjective
Fraught with uncertainty or doubt; "they were doubtful that the cord would hold"; "it was doubtful whether she would be admitted"; "dubious about agreeing to go" [syn: doubtful, dubious]
adjective
Unsettled in mind or opinion; "drew a few tentative conclusions" [syn: doubtful, tentative]

Definition of 'Doubtful'

From: GCIDE
  • Doubtful \Doubt"ful\, a.
  • 1. 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. [1913 Webster]
  • Methinks I should know you, and know this man; Yet I am doubtful. --Shak. [1913 Webster]
  • With doubtful feet and wavering resolution. --Milton. [1913 Webster]
  • 2. Admitting of doubt; not obvious, clear, or certain; questionable; not decided; not easy to be defined, classed, or named; as, a doubtful case, hue, claim, title, species, and the like. [1913 Webster]
  • Beauty is but a vain and doubtful good. --Shak. [1913 Webster]
  • Is it a great cruelty to expel from our abode the enemy of our peace, or even the doubtful friend [i. e., one as to whose sincerity there may be doubts]? --Bancroft. [1913 Webster]
  • 3. Characterized by ambiguity; dubious; as, a doubtful expression; a doubtful phrase. [1913 Webster]
  • 4. Of uncertain issue or event. [1913 Webster]
  • We . . . have sustained one day in doubtful fight. --Milton. [1913 Webster]
  • The strife between the two principles had been long, fierce, and doubtful. --Macaulay. [1913 Webster]
  • 5. Fearful; apprehensive; suspicious. [Obs.] [1913 Webster]
  • I am doubtful that you have been conjunct And bosomed with her. --Shak.
  • Syn: Wavering; vacillating; hesitating; undetermined; distrustful; dubious; uncertain; equivocal; ambiguous; problematical; questionable. [1913 Webster]

Synonyms of 'doubtful'

From: Moby Thesaurus