hypothesis

noun

1. 1

   Used loosely, a tentative conjecture explaining an observation, phenomenon or scientific problem that can be tested by further observation, investigation and/or experimentation. As a scientific term of art, see the attached quotation. Compare to theory, and quotation given there.

2. 2

   (general) An assumption taken to be true for the purpose of argument or investigation.

3. 3

   (grammar) The antecedent of a conditional statement.