Source : Webster's Revised Unabridged Dictionary (1913)

Dubitable \Du"bi*ta*ble\, a. [L. dubitabilis. Cf. {Doubtable}.]
   Liable to be doubted; uncertain. [R.] --Dr. H. More. --
   {Du"bi*ta*bly}, adv. [R.]

Source : WordNet®

dubitable
     adj : 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}, {in question(p)}]