*decretory*

a. [ L. decretorius, from decretum. See Decree. ] 1. Established by a decree; definitive; settled. [ 1913 Webster ]

The decretory rigors of a condemning sentence. South. [ 1913 Webster ]

2. Serving to determine; critical. “The critical or decretory days.” Sir T. Browne. [ 1913 Webster ]