(astronomy) A radially pulsating (expanding and contracting) variable star with a regular period and known relationship between period and intrinsic brightness.

(physics) A variable whose value is determined by measuring a difference of the values at two extreme points of an element; thus voltage is a difference in two levels of potential.

(physics) any parameter that would supplement quantum mechanics so as to make it like classical mechanics; local hidden variables have been proved to be inconsistent with quantum mechanics

(astronomy) A star in which the strength of the helium absorption lines vary periodically; at times appearing to be a helium star.

(programming) the association between a variable name (identifier) and its value.

(programming) A variable that is associated with a value, and therefore a variable that has an allocated storage location. If the programming language implements a representation of a canonical unknown value, infinity, etc., the value bound to the variable may be one of these.

(programming) A variable that is not bound to a storage location.

(mathematics, logic, computing) Any variable, from the domain of Boolean algebra, having one of only two values

(astronomy) Any star whose brightness varies.

(computing) A variable used for storing the address of another variable or structure, equivalent to a pointer.