DictionarysupposeAssume to be true
verb

suppose

suh-POHZ/səˈpəʊz/

To assume a condition to be true or intended.

The man supposes a book lies inside the unopened box.

Man looks at closed box with uncertain face, small thought bubble proposes one book inside while question mark indicates uncertainty; box remains closed, no factual reveal or words.
Etymology

Old French suposer meant “to assume.” In English, taking something as a basis for argument developed into believing it true without being certain.

In context

Enhanced Public Domain168:54
few of us ever ask ourselves for example what reason there is to suppose the food we are just going to eat will not turn out to be poison
1910s Philosophy: Bertrand Russell - The Problems of Philosophy (Audiobook)

More examples

  • Let's suppose we miss the last bus.
  • You're supposed to sign in before entering the lab.
  • This switch is supposed to turn on the porch light.

Forms

suppose · supposes · supposed · supposing

supposition noun — An idea accepted as true without proof.

Similar words

assume
More directly treats something unverified as an established fact.
presume
Often suggests a belief based on probability or reasonable evidence.