The Collaborative International Dictionary of English v.0.48:

Dehonestate \De`ho*nes"tate\, v. t. [L. dehonestatus, p. p. of
   dehonestare to dishonor; de- + honestare to make honorable.
   Cf. Dishonest, and see Honest.]
   To disparage. [Obs.]
   [1913 Webster]