Definitions for "Marginal product"
the increase in output resulting from the use of an additional unit of an input or factor of production.
In a production function, the marginal product of a factor is the increase in output due to a unit increase in the input of the factor; that is, the partial derivative of the production function with respect to the factor. In a competitive equilibrium, the equilibrium price of any factor is its marginal value product in every sector where it is employed.
The addition to total output due to the addition of the last unit of an input (when the quantity of other inputs is held constant).