n.; pl. Hypotheses [ NL., fr. Gr. &unr_; foundation, supposition, fr. &unr_; to place under, &unr_; under + &unr_; to put. See Hypo-, Thesis. ] 1. A supposition; a proposition or principle which is supposed or taken for granted, in order to draw a conclusion or inference for proof of the point in question; something not proved, but assumed for the purpose of argument, or to account for a fact or an occurrence; as, the hypothesis that head winds detain an overdue steamer. [ 1913 Webster ]
An hypothesis being a mere supposition, there are no other limits to hypotheses than those of the human imagination. J. S. Mill. [ 1913 Webster ]
2. (Natural Science) A tentative theory or supposition provisionally adopted to explain certain facts, and to guide in the investigation of others; hence, frequently called a working hypothesis.
Syn. -- Supposition; assumption. See Theory. [ 1913 Webster ]
Nebular hypothesis. See under Nebular.