The definition of inbound is something that moves inward. An example of inbound is the freeway that goes toward the city center. 1  traveling or going inward.  Basketball inbounds.
Mass is a measurement of how much matter is in an object. Mass is a combination of the total number of atoms, the density of the atoms, and the type of atoms in an object. How to Measure Mass.
Matter is anything that has mass and volume. The mass of matter is measured by the acceleration a body has when a force is applied. The greater the mass, the slower the acceleration for the same force.