Source : Webster's Revised Unabridged Dictionary (1913)

Forethink \Fore*think"\, v. t.
   1. To think beforehand; to anticipate in the mind; to
      prognosticate. [Obs.]

            The soul of every man Prophetically doth forethink
            thy fall.                             --Shak.

   2. To contrive (something) beforehend. [Obs.] --Bp. Hall.

Forethink \Fore*think"\, v. i.
   To contrive beforehand. [Obs.]