The impetus behind all motion and all activity. / The capacity to do work.

plural of energy

(physics) The energy possessed by an object because of its motion, equal (nonrelativistically) to one half the mass of the body times the square of its speed.

(alternative medicine) The spiritual or etheric energy produced by an individual living being.

(physics) of an elementary particle, or the equivalent electromagnetic radiation, having an energy greater than a hundred thousand electron volts

The energy possessed by an object because of its position (in a gravitational or electric field), or its condition (as a stretched or compressed spring, as a chemical reactant, or by having rest mass).

(physics) A property, characteristic of the state of a thermodynamic system, the change of which is equal to the heat absorbed minus the work done by the system.

(physics) Any of the discrete stable energies that a quantum mechanical system (such as the electrons of an atom) can have. / Used other than figuratively or idiomatically: see energy, level.

(chemistry) The net potential energy liberated or absorbed during the course of a chemical reaction

heat under the ground used to heat water and make steam to turn generator turbines and make electricity.