Supposition

noun/ˌsʌpəˈzɪʃən/philosophy

Definition

An uncertain belief.

Etymology

From Middle English supposicioun, from Anglo-Norman supposicion, from Latin suppositiō, suppositiōnem (“supposition”), from sub- (“under”) + positiō, positiōnem (“position; theme”), from positus (“position”), from the perfect passive participle of pōnō, pōnere (“put, place”).

Synonyms

surmise, conjecture, hypothesis, speculation, guess

In a sentence

That's a supposition, not a conclusion — we need data.