IPA: /səˈpəʊzɪʃənl/
KK: /səˈpəʊzɪʃənl/
Based on an assumption or something that is not proven; often used to describe ideas or theories that are imagined rather than real.
The scientist presented a suppositional theory about the origins of the universe.
Suppositional → It is formed from "suppositio" (from Latin, meaning a placing under or a hypothesis) and the suffix "-al" (meaning relating to). The word "suppositional" refers to something that is related to or based on a hypothesis or assumption.
Think of 'placing under' (from 'suppositio') to remember that 'suppositional' relates to something based on a hypothesis or assumption.