energy

Etymology

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”).

Pronunciation

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

• Audio (US)

  (file)

Noun

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, George A. Birmingham, “chapter I”, in Gossamer (Project Gutenberg; EBook #24394), London: Methuen & Co., published 8 January 2013 (Project Gutenberg version), OCLC 558189256:

     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.

   Units:

   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. (New Age jargon) An intangible, modifiable force (often characterized as either 'positive' or 'negative') believed 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.
   • 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.

Anagrams

• Greeny, greeny, greyen, gyrene