Lewis Short
(adjective) : dēcrētōrĭus, a, um, id.
* Belonging to a decision, decisive (post-Aug.): non accedit ad decretorium stilum,i. e. to a definitive sentence,Sen. Clem. 1, 14: intrepidus horam illam decretoriam (viz., the hour of death) prospice,id. Ep. 102 med.; so, dies,Plin. 18, 29, 69, § 288; cf. id. 18, 28, 68, § 272: arma,Sen. Ep. 117 med.; so Quint. 10, 5, 20: pugna,id. 6, 4, 6.
Charlton T. Lewis, Charles Short, A Latin Dictionary