Definition of "free energy" []

• A thermodynamic quantity that is the difference between the internal energy of a system and the product of its absolute temperature and entropy. (noun)
• A thermodynamic quantity that is the difference between the enthalpy and the product of the absolute temperature and entropy of a system. Also called Gibbs free energy. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.