What is defined as the force that gravity exerts on an object?

Weight is defined as the force that gravity exerts on an object. It is a measure of the gravitational pull acting on an object's mass. The weight of an object depends not only on its mass but also on the acceleration due to gravity at the location of the object. As such, weight can be calculated using the formula:

Weight (W) = mass (m) × gravitational acceleration (g)

In contrast, mass is a measure of the amount of matter in an object and does not vary with gravity; it remains constant regardless of location in the universe. Inertia refers to the property of an object to resist changes in its state of motion, while weightlessness refers to the sensation or condition of being free from the effects of gravity, which occurs in free-fall or in orbit. Weight, being the direct result of gravitational forces, is what differentiates it from these other concepts.