The Collaborative International Dictionary of English v.0.48:

Thereout \There*out"\, adv.
   1. Out of that or this.
      [1913 Webster]

            He shall take thereout his handful of the flour.
                                                  --Lev. ii. 2.
      [1913 Webster]

   2. On the outside; out of doors. [Obs.] --Chaucer.
      [1913 Webster]