Decretive is an adjective that refers to the issuance of a decree, which is an official order or decision made by a person in authority. Some synonyms that can be used in place of decretive include authoritative, commanding, decisive, directive, imperious, and peremptory. Each of these words suggests a sense of explicit and uncompromising authority that can be associated with the act of issuing a decree. Decisive and peremptory, for example, both imply a sense of finality and certainty that may be used to describe the nature of a decree. However, each of these words also has its own distinctive connotations that may be better suited to certain contexts and purposes.