The Collaborative International Dictionary of English v.0.48:

Dubitative \Du"bi*ta*tive\, a. [L. dubitativus: cf. F.
   dubitatif.]
   Tending to doubt; doubtful. [R.] -- Du"bi*ta*tive*ly, adv.
   [R.] --. Eliot.
   [1913 Webster]