en·er·gy | \ˈe-nər-jē \
plural energies

Definition of energy 

1a : 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

Keep scrolling for more

Choose the Right Synonym for 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

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.
See More

Recent Examples on the Web

Here’s hoping that Brown saves his energy for the sultry and cranky sounds of his most recent double album, Heartbreak on a Full Moon, in Camden. Grace Dickinson,, "Taylor Swift, 'Star Wars' with The Philadelphia Orchestra, and other great events in Philadelphia, July 13-20," 12 July 2018 After Devo went on an extended hiatus in the 1990s, Casale channeled his energy by moving into commercial directing — and wine-making. Randall Roberts,, "The Art of De-Evolution: Mark Mothersbaugh and Gerald Casale discuss two new books that celebrate punk band Devo's visual work," 12 July 2018 The suggestion that lost, angry young men might do better to channel their energies towards basic grooming and life skills is not an unhelpful one. Laurie Penny, Longreads, "Peterson’s Complaint," 12 July 2018 This would simultaneously help advance the president’s climate and clean energy goals while offering consumers a bit of a break while the cost of battery technology slowly came down. Sean O'kane, The Verge, "Tesla will be the first automaker to lose the federal tax credit for electric cars," 12 July 2018 At the same time, to watch this footage is to root for him, and to receive his energy, not as an imposition, but as a generous act. Mick Lasalle,, "Robin Williams gets his just due in documentary ‘Come Inside My Mind’," 11 July 2018 Every single song is a bop, and their energy onstage is contagious. Chris Varias,, "10 not-to-miss bands at final Vans Warped Tour," 11 July 2018 But Germany imports just 9 percent of all of its energy, which undercuts Trump’s claim that Germany will somehow be beholden to Moscow. Alex Ward, Vox, "Trump blasted US allies within minutes of arriving at NATO summit," 11 July 2018 Taggart has saved his energy for fighting the cancer. Lori Nickel, Milwaukee Journal Sentinel, "Patient takes the fight to cancer with Scenic Shore team raising hundreds of thousands of dollars," 10 July 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.

See More

First Known Use of energy

1599, in the meaning defined at sense 1a

History and Etymology for energy

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

Keep scrolling for more

Learn More about energy

Statistics for energy

Last Updated

17 Oct 2018

Look-up Popularity

Time Traveler for energy

The first known use of energy was in 1599

See more words from the same year

Keep scrolling for more

More Definitions for energy



English Language Learners Definition of energy

: 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.


en·er·gy | \ˈe-nər-jē \
plural energies

Kids Definition of energy

1 : ability to be active : strength of body or mind to do things or to work The children … were tired and hardly had energy enough to walk.— E. B. White, Charlotte's Web

2 : strong action or effort He puts a lot of energy into his work.

3 : usable power or the resources (as oil) used to produce usable power Our new dryer uses a lot less energy.


en·er·gy | \ˈen-ər-jē \
plural energies

Medical Definition of energy 

2 : the capacity for doing work

Keep scrolling for more

More from Merriam-Webster on energy

Thesaurus: All synonyms and antonyms for energy

Spanish Central: Translation of energy

Nglish: Translation of energy for Spanish Speakers

Britannica English: Translation of energy for Arabic Speakers

Comments on energy

What made you want to look up energy? Please tell us where you read or heard it (including the quote, if possible).


lying above or upon

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Roman Mythology Quiz

  • the-triumph-of-venus-by-alessandro-magnasco
  • Boreal comes from the name of the ancient Greek god of which wind?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!