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 quantum physics, mass can be described as the amount of potential energy contained within a body, and is a measurement of how much energy would be liberated should that mass be converted into energy through mass annihilation using the famous E=mc2 equation. It could also mean church.