weight

weight, measure, expressed in pounds or grams, of the force of gravity on a body. Because the weights of different bodies at the same location are proportional to their masses, weight is often used to determine mass. Unlike the mass, the weight of a body depends on its location in the gravitational field of the earth or of some other astronomical body. An object in space may be weightless, but will still have the same mass as it does on the earth, and thus will require a force to make it move.