from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. The capacity for work or vigorous activity; vigor; power. See Synonyms at strength.
  • n. Exertion of vigor or power: a project requiring a great deal of time and energy.
  • n. Vitality and intensity of expression: a speech delivered with energy and emotion.
  • n. Usable heat or power: Each year Americans consume a high percentage of the world's energy.
  • n. A source of usable power, such as petroleum or coal.
  • n. Physics The capacity of a physical system to do work.

from Wiktionary, Creative Commons Attribution/Share-Alike License

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

from the GNU version of the Collaborative International Dictionary of English

  • n. Internal or inherent power; capacity of acting, operating, or producing an effect, whether exerted or not.
  • n. Power efficiently and forcibly exerted; vigorous or effectual operation.
  • n. Strength of expression; force of utterance; power to impress the mind and arouse the feelings; life; spirit; -- said of speech, language, words, style.
  • n. Capacity for performing work.

from The Century Dictionary and Cyclopedia

  • n. The actual exertion of power; power exerted; strength in action; vigorous operation.
  • n. Activity considered as a characteristic; habitual putting forth of power or strength, physical or mental, or readiness to exert it.
  • n. The exertion of or capacity for a particular kind of force; action or the power of acting in any manner; special ability or agency: used of the active faculties or modes of action regarded severally, and often in the plural: as, creative energy; the energies of mind and body.
  • n. In the Aristotelian philos., actuality; realization; existence; the being no longer in germ or in posse, but in life or in esse: opposed to power, potency, or potentiality.
  • n. A fact of acting or actually being.
  • n. In rhetoric, the quality of awakening the imagination of the reader or hearer, and bringing the meaning of what is said home to him; liveliness.
  • n. In physics: Half the sum of the masses of the particles of a system each multiplied by the square of its velocity; half the vis viva. See vis viva.
  • n. Half the greatest value to which the sum of the masses of all the particles of a given system each multiplied by the square of its velocity, could attain except for friction, viscosity, and other forces dependent on the velocities of the particles; otherwise, the amount of work (see work) which a given system could perform were it not for resistance dependent on the velocities.
  • n. of water in motion, or in an elevated position;
  • n. of air in motion, as the wind;
  • n. the muscular energy of animals. To these might be added the energy of direct solar radiation, the energy of the tides, and some others of less importance. The source of all these forms of energy, except that of the tides, is to be found in the radiant energy of the sun.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. a healthy capacity for vigorous activity
  • n. any source of usable power
  • n. enterprising or ambitious drive
  • n. the federal department responsible for maintaining a national energy policy of the United States; created in 1977
  • n. forceful exertion
  • n. (physics) a thermodynamic quantity equivalent to the capacity of a physical system to do work; the units of energy are joules or ergs
  • n. an imaginative lively style (especially style of writing)


from The American Heritage® Dictionary of the English Language, 4th Edition

French énergie, from Late Latin energīa, from Greek energeia, from energos, active : en-, in, at; see en-2 + ergon, work; see werg- in Indo-European roots.

from Wiktionary, Creative Commons Attribution/Share-Alike License

From Ancient Greek ἐνέργεια (energeia, "action, act, work"), from ἐνεργός (energos, "active"), from ἐν (en, "in") + ἔργον (ergon, "work").


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  • "Hundreds of thousands, if not millions, of tenant farmers who had resided in rural hamlets, living off common land, suddenly found their ancient lifestyle upended by a long wave of privatization. Those newly free-floating laborers became another, equally essential, energy source for the Industrial Revolution, filling its cities and coketowns with a nearly inexhaustible supply of cheap labor. In a sense, the Industrial Revolution would never have happened if two distinct forms of energy had not been separated from the earth: coal and commoners."

    —Steven Johnson, The Ghost Map (New York: Penguin, 2006), 94

    October 1, 2008

  • *bounces in his chair*

    September 12, 2008