Transumption is a rare and uncommon word that means the act of assuming or taking something for granted without proof or evidence. Though this word may not be familiar, there are several synonyms that can be used in its place. Some of the synonyms for transumption include presumption, supposition, assumption, conjecture, speculation, and hypothesis. Each of these words shares a similar meaning and can be used interchangeably in many cases. By using these synonyms, one can ensure proper understanding and avoid confusion when communicating their thoughts and ideas.