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.
mass. 1  a body of coherent matter, usually of indefinite shape and often of considerable size: a mass of dough. 2  a collection of incoherent particles, parts, or objects regarded as forming one body: a mass of sand. 3  aggregate; whole (usually preceded by in the): People, in the mass, mean well.