Source : Webster's Revised Unabridged Dictionary (1913)

Decretory \Dec"re*to*ry\, a. [L. decretorius, from decretum. See
   {Decree}.]
   1. Established by a decree; definitive; settled.

            The decretory rigors of a condemning sentence.
                                                  --South.

   2. Serving to determine; critical. ``The critical or
      decretory days.'' --Sir T. Browne.