The Collaborative International Dictionary of English v.0.48:

Cohobate \Co`ho*bate\, v. t. [imp. & p. p. Cohobated; p. pr. &
   vb. n. Cohobating.] [LL. cohobare; prob. of Arabic origin:
   cf. F. cohober.] (Anc. Chem.)
   To repeat the distillation of, pouring the liquor back upon
   the matter remaining in the vessel. --Arbuthnot.
   [1913 Webster]