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.
In physical science, mass refers to the degree of acceleration a body acquires when subject to a force: bodies with greater mass are accelerated less by the same force. One says the body of greater mass has greater inertia.