The Collaborative International Dictionary of English v.0.48:

Indubitate \In*du"bi*tate\, a. [L. indubitatus; pref. in- not +
   dubitatus, p. p. of dubitare to doubt.]
   Not questioned or doubtful; evident; certain. [Obs.] --Bacon.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Indubitate \In*du"bi*tate\, v. t. [L. indubitatus, p. p. of
   indubitare; pref. in- in + dubitare to doubt.]
   To bring into doubt; to cause to be doubted. [Obs.]
   [1913 Webster]

         To conceal, or indubitate, his exigency. --Sir T.
                                                  Browne.
   [1913 Webster]