Postulatory is an adjective that refers to something related to postulation or the act of making a proposal or suggestion. Some synonyms for this word include conjectural, speculative, hypothetical, and suppositional. Other similar words include presumptive, theoretical, putative, and imagined. These words are often used interchangeably to describe something that is based on assumptions rather than facts. They are commonly used in academic and scientific research to refer to ideas or theories that require further investigation and evidence. Overall, postulatory and its synonyms are useful words that can help improve the clarity and precision of your writing.