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

plural of energy

(physics) A measure of the bending of ingoing and outgoing rays of light that are orthogonal to a 2-sphere surrounding a region of space whose mass is to be defined.

(mathematical analysis, functional analysis, Fourier analysis) A quadratic functional which, given a real function defined on an open subset of ℝⁿ, yields a real number that is a measure of how variable said function is.

(cosmology, astrophysics, astronomy, physics) A category of dark energy, where dark energy is not fixed in amount nor in density, and continuously increases over time.

(energy efficiency) The energy that is lost due to standby electronic activity of equipment that is "off", on standby or sleep mode.

(informal) A device or appliance that uses electricity even while switched off. / (informal, derogatory) A person who is emotionally draining.

plural of energy vampire

A designated area for the generation of clean energy such as wind and solar power.

plural of energy park