In
chemical thermodynamics, an
endergonic reaction (also called a
nonspontaneous reaction or an
unfavorable reaction) is a
chemical reaction in which the standard change in
free energy is positive, and energy is absorbed. In layman's terms, the total amount of energy is a loss (it takes more energy to start the reaction than what you get out of it) so the total energy is a negative net result. For an overall gain in the net result see
exergonic reaction.