noun (plural hypotheses |-ˌsēz| )

a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation:

｟かたく｠ «…についての/…という» 仮説 «about, for/that節» (→ theory); 〘数〙 仮説

e.g. professional astronomers attacked him for popularizing an unconfirmed hypothesis.

Philosophy a proposition made as a basis for reasoning, without any assumption of its truth.

(議論の)前提

late 16th century: via late Latin from Greek hupothesis ‘foundation’, from hupo ‘under’ + thesis ‘placing’.