The antecedent of a conditional statement.
An assumption taken to be true for the purpose of argument or investigation.
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.
the condition upon which something is presumed
the belief of something based upon reasonable evidence, or upon something known to be true
the act of presuming, or something presumed
An inference that a trier of fact is either permitted or required to draw under certain factual circumstances (as prescribed by statute or case law) unless the party against whom the inference is drawn is able to rebut it with admissible, competent evidence.