Hȳ-pŏth'e-sĭs or Hĭ-pŏth'e-sĭs, n.

n.; pl. HY-PŎTH'E-SĒS (hī-, or hĭ-). [Gr. ὑπόθεσις, foundation, supposition, from ὑποτιθέναι, to place under; N. Lat. hypothesis, Fr. hypothèse.]

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.
2. A system or theory imagined or assumed to account for known facts or phenomena.

Syn.—Theory; supposition; assumption. See THEORY.