From Middle French énergie, from Late Latin energia, from Ancient Greek ἐνέργεια (enérgeia, activity), from ἐνεργός (energós, active), from ἐν (en, in) + ἔργον (érgon, work). The sense in physics was coined by Thomas Young in 1802 in his lectures on Natural Philosophy.


  • (UK) IPA(key): /ˈɛnəd͡ʒi/
  • (US) IPA(key): /ˈɛnɚd͡ʒi/
  • (file)


energy (countable and uncountable, plural energies)

  1. The impetus behind all motion and all activity.
    • 2013 June 1, “Ideas coming down the track”, in The Economist, volume 407, number 8838, page 13 (Technology Quarterly):
      A “moving platform” scheme [] is more technologically ambitious than maglev trains even though it relies on conventional rails. [] This set-up solves several problems […]. Stopping high-speed trains wastes energy and time, so why not simply slow them down enough for a moving platform to pull alongside?
  2. The capacity to do work.
    • 1915, G[eorge] A. Birmingham [pseudonym; James Owen Hannay], chapter I, in Gossamer, New York, N.Y.: George H. Doran Company, OCLC 5661828:
      There is an hour or two, after the passengers have embarked, which is disquieting and fussy. [] Stewards, carrying cabin trunks, swarm in the corridors. Passengers wander restlessly about or hurry, with futile energy, from place to place.
  3. (physics) A quantity that denotes the ability to do work and is measured in a unit dimensioned in mass × distance²/time² (ML²/T²) or the equivalent.
    SI: joule (J), kilowatt-hour (kW·h)
    CGS: erg (erg)
    Customary: foot-pound-force, calorie, kilocalorie (i.e. dietary calories), BTU, liter-atmosphere, ton of TNT
  4. An intangible, modifiable force (often characterized as either 'positive' or 'negative') believed in some New Age religions to emanate from a person, place or thing and which is (or can be) preserved and transferred in human interactions; shared mood or group habit; a vibe, a feeling, an impression. (Compare aura.)
    • 2004, Phylameana L. Desy, The Everything Reiki Book, Body, Mind & Spirit, p.130
      Reiki, much like prayer, is a personal exercise that can easily convert negative energy into positive energy.
    • 2009, Christopher Johns, Becoming a Reflective Practitioner, John Wiley & Sons, p.15
      Negative feelings can be worked through and their energy converted into positive energy []. In crisis, normal patterns of self-organization fail, resulting in anxiety (negative energy). Being open systems, people can exchange this energy with the environment and create positive energy for taking action based on a reorganisation of self as necessary to resolve the crisis and emerge at a higher level of consciousness; that is, until the next crisis.
    • 2011, Anne Jones, Healing Negative Energies, Hachette, p.118
      If you have been badly affected by negative energy a salt bath is wonderful for clearing and cleansing yourself []. Salt attracts negative energy and will draw it away from you.
  5. (role-playing games, video games, board games) A measure of how many actions a player or unit can take; in the fantasy genre often called magic points or mana.
    Synonym: action points



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  • Cebuano: enerdyi



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