Definition: Mass; The amount of matter in an object. Mass is not dependent on gravity. Mass is different from the weight of an object. - Mass
Examples: Mass is the property of a body that is a measure of its inertia (lacking the power to move). Mass is commonly taken as a measure of the amount of material it contains and causes it to have weight within Earth's gravity. (Mass is different from "weight." What you weigh has to do with gravity; your mass is measured without gravity.)