definition of
hypothesis

[1] #1 hypothesis n. a proposal intended to explain certain facts or observations. wn

[2] #2 hypothesis n. [possibility, theory] a tentative insight into the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena; "a scientific hypothesis that survives experimental testing becomes a scientific theory"; "he proposed a fresh theory. wn

[3] #3 hypothesis n. [guess, conjecture, supposition, surmise, surmisal, speculation] a message expressing an opinion based on incomplete evidence. wn