See payload in Webster's New World College Dictionary
noun
a cargo, or the part of a cargo, producing income
a load that consists of anything carried by an aircraft, rocket, etc. that is not essential to its flight operations, including warheads, spacecraft, or passengers
the weight of such a load
See payload in American Heritage Dictionary 4
noun
The revenue-producing part of a cargo.
a. The total weight of passengers and cargo that an aircraft carries or can carry.
b. The total weight of the instruments, crew, and life-support systems that a spacecraft carries or can carry.
c. The passengers, crew, instruments, or equipment carried by an aircraft, spacecraft, or rocket.
The explosive charge carried in the warhead of a missile.