energy

[en-er-jee]

noun, plural en·er·gies.


Origin of energy

1575–85; < Late Latin energīa < Greek enérgeia activity, equivalent to energe- (stem of energeîn to be active; see en-2, work) + -ia -y3
Related formshy·per·en·er·gy, nounself-en·er·gy, noun

Synonyms for energy

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for energy

Contemporary Examples of energy

Historical Examples of energy

  • He had sat in the background, but he had found both money and energy.

  • He rose with the blow; all his energy, from wrist to instep, was in that lifting drive.

  • Then abruptly, the young man spoke with the energy of perfect faith in the woman.

    Within the Law

    Marvin Dana

  • You have health and energy, and you have youth, which I haven't.

    K

    Mary Roberts Rinehart

  • The Satanic energy of this outburst proclaims its author, Marlowe.



British Dictionary definitions for energy

energy

noun plural -gies

intensity or vitality of action or expression; forcefulness
capacity or tendency for intense activity; vigour
vigorous or intense action; exertion
physics
  1. the capacity of a body or system to do work
  2. a measure of this capacity, expressed as the work that it does in changing to some specified reference state. It is measured in joules (SI units)Symbol: E
a source of powerSee also kinetic energy, potential energy

Word Origin for energy

C16: from Late Latin energīa, from Greek energeia activity, from energos effective, from en- ² + ergon work
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for energy
n.

1590s, "force of expression," from Middle French énergie (16c.), from Late Latin energia, from Greek energeia "activity, operation," from energos "active, working," from en "at" (see en- (2)) + ergon "work, that which is wrought; business; action" (see urge (v.)).

Used by Aristotle with a sense of "force of expression;" broader meaning of "power" is first recorded in English 1660s. Scientific use is from 1807. Energy crisis first attested 1970.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for energy

energy

[ĕnər-jē]

n.

The capacity for work or vigorous activity; vigor; power.
The capacity of a physical system to do work.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for energy

energy

[ĕnər-jē]

The capacity or power to do work, such as the capacity to move an object (of a given mass) by the application of force. Energy can exist in a variety of forms, such as electrical, mechanical, chemical, thermal, or nuclear, and can be transformed from one form to another. It is measured by the amount of work done, usually in joules or watts. See also conservation of energy kinetic energy potential energy. Compare power work.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for energy

energy

In physics, the ability to do work. Objects can have energy by virtue of their motion (kinetic energy), by virtue of their position (potential energy), or by virtue of their mass (see E = mc2).

Note

The most important property of energy is that it is conserved — that is, the total energy of an isolated system does not change with time. This is known as the law of conservation of energy. Energy can, however, change form; for example, it can be turned into mass and back again into energy.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.