Real Dictionary

hypothesis
variable noun: A hypothesis is an idea which is suggested as a possible explanation for a particular situation or condition, but which has not yet been proved to be correct.

hypothesis in American English
an unproved theory, proposition, supposition, etc. tentatively accepted to explain certain facts or (working hypothesis) to provide a basis for further investigation, argument, etc.
noun: a proposition, or set of propositions, set forth as an explanation for the occurrence of some specified group of phenomena, either asserted merely as a provisional conjecture to guide investigation (working hypothesis) or accepted as highly probable in th

hypothesis in British English
noun: a suggested explanation for a group of facts or phenomena, either accepted as a basis for further verification ( working hypothesis) or accepted as likely to be true