1.nounA conserved property of the light in an optical system which characterizes how "spread out" the light is in terms of angle and area: it is the product of its cross-sectional area (normal to the direction of propagation) and the solid angle it subtends.
2.nounThe rate at which data is transferred through a system.
3.noun(operations) The rate of production; the rate at which something can be processed.
"The factory managed a throughput of 120 units per hour."