Preordaining is a word that refers to the process of establishing or deciding something in advance. It implies that a particular event or outcome has already been determined prior to its occurrence. When looking for synonyms for this concept, one could consider other phrases such as predetermined, predestined, foreordained, fated, or destined. Each of these words conveys the idea of something being pre-established or pre-determined, often by a higher power or force. These terms are often used in discussions of fate, destiny, or divine intervention. Overall, synonyms for preordaining suggest a sense of inevitability or predestination in regards to the future.