premise

A proposition antecedently supposed or proved; something previously stated or assumed as the basis of further argument; a condition; a supposition.

(logic) Any of the first propositions of a syllogism, from which the conclusion is deduced.

(usually in the plural, law) Matters previously stated or set forth; especially, that part in the beginning of a deed, the office of which is to express the grantor and grantee, and the land or thing granted or conveyed, and all that precedes the habendum; the thing demised or granted.

(usually in the plural) A piece of real estate; a building and its adjuncts.

(authorship) The fundamental concept that drives the plot of a film or other story.