The American Heritage® Dictionary of the English Language, 4th Edition
n. A thermodynamic function of a system, equivalent to the sum of the internal energy of the system plus the product of its volume multiplied by the pressure exerted on it by its surroundings.
n. In thermodynamics, a measure of the heat content of a chemical or physical system.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. (thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure
Word Usage
"To reach that end, Perkins+Will has used the latest sustainable technologies, such as enthalpy wheels that capture wind-generated warmth and wind turbines driven by tropical breezes."