energy

noun en·er·gy \ ˈe-nər-jē \

Updated on: 19 Apr 2018

Definition of energy

plural energies

1 a : dynamic quality

narrative energy

b : the capacity of acting or being active

intellectual energy

c : a usually positive spiritual force

the energy flowing through all people

2 : vigorous exertion of power : effort

investing time and energy

3 : a fundamental entity of nature that is transferred between parts of a system in the production of physical change within the system and usually regarded as the capacity for doing work

4 : usable power (such as heat or electricity); also : the resources for producing such power

See energy defined for English-language learners

See energy defined for kids

Examples of energy in a Sentence

The kids are always so full of energy.
They devoted all their energy to the completion of the project.
They devoted all their energies to the completion of the project.
She puts a lot of energy into her work.
The newer appliances conserve more energy.

Recent Examples of energy from the Web

To feed the city’s unquenchable thirst for energy, Dubai recently broke ground on the world’s largest single-site solar park.

— Bloomberg.com, "A City Reaching for the Sky, Without the Help of Oil," 16 Apr. 2018
With abundant energy emanating from the moon’s interior into the ocean, scientists speculate life might exist—probably just microbes, but why not something krill-like, too?

— eric berger, Ars Technica, "The billion-dollar question: How does the Clipper mission get to Europa?," 16 Apr. 2018
Her passion and energy were intense – her laughter was distinctive and infectious.

— brandon patterson, Detroit Free Press, "Eastern Michigan professor fatally struck by car while walking dog," 16 Apr. 2018
Jason Terry had three points and was a net-neutral in his 18 minutes and Tyler Zeller provided some energy with a steal for a dunk during his 4 1/2 minutes on the floor.

— matt velazquez, Milwaukee Journal Sentinel, "Bucks confident they can get more from Jabari Parker, role players in Game 2," 16 Apr. 2018
These ketones can be used by the body and brain for energy.

— sheah rarback, miamiherald, "Research shows ketogenic diet could be helpful for diabetics | Miami Herald," 16 Apr. 2018
And against a team like Marriotts Ridge, undefeated and ranked nationally ranked by US Lacrosse Magazine, Pagnatta wanted to preserve the energy of those players.

— kyle stackpole, Howard County Times, "Glenelg girls lacrosse hands Marriotts Ridge first loss," 14 Apr. 2018
Apple added that nine of its manufacturing partners have also agreed to power facilities that produce the company’s products on clean energy, bringing that total number to 23 partners.

— don reisinger, Fortune, "Apple Releases New iPhone as HomePod Sales Disappoint," 14 Apr. 2018
Anna had told me that her parents worked in solar energy.

— rachel deloache williams, The Hive, "“As an Added Bonus, She Paid for Everything”: My Bright-Lights Misadventure with a Magician of Manhattan," 13 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'energy.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of energy

Late Latin energia, from Greek energeia activity, from energos active, from en in + ergon work — more at work

NEW! Time Traveler

First Known Use: 1599

See Words from the same year

energy Synonyms

Synonym Discussion of energy

power, force, energy, strength, might mean the ability to exert effort. power may imply latent or exerted physical, mental, or spiritual ability to act or be acted upon.

- the awesome power of flowing water

force implies the actual effective exercise of power.

- used enough force to push the door open

energy applies to power expended or capable of being transformed into work.

- a worker with boundless energy

strength applies to the quality or property of a person or thing that makes possible the exertion of force or the withstanding of strain, pressure, or attack.

- use weight training to build your strength

might implies great or overwhelming power or strength.

- the belief that might makes right

Other Physics Terms

amplitude, centrifugal, centripetal, convection, gradient, hysteresis, kinetic, lase, quantum

ENERGY Defined for English Language Learners

energy

noun

Definition of energy for English Language Learners

: ability to be active : the physical or mental strength that allows you to do things
: natural enthusiasm and effort
: usable power that comes from heat, electricity, etc.