energy

noun

en·​er·​gy ˈe-nər-jē 

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

Synonyms

• qi
• aura
• spirit
• chi
• life
• light
• ki

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.

Recent Examples on the Web

China unveiled a new national energy law at the beginning of 2025 to coordinate its many energy-centric efforts. —Ariel Cohen, Forbes.com, 8 Aug. 2025

Cape Town, too, balances urban energy with natural grandeur. —Erina Pinar, Travel + Leisure, 7 Aug. 2025

Pets also often develop fever and swollen lymph nodes, and may also have low energy or lose their appetites. —Meg Wingerter, Denver Post, 7 Aug. 2025

Instead, the real meat on the bones is secondary tariffs of 100% on importers of Russian energy, such as India and China, who indirectly provide the Kremlin with tens of billions of dollars that finance its war effort. —Daniel Depetris, Time, 7 Aug. 2025

Word History

Etymology

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

First Known Use

1783, in the meaning defined at sense 1a

Phrases Containing energy

• activation energy
• alternative energy
• atomic energy
• binding energy
• bundle of energy
• conservation of energy
• dark energy
• dual energy X-ray absorptiometry
• energy drink
• energy level
• high-energy
• high-energy physics
• kinetic energy
• luminous energy
• nervous energy
• non-energy
• nuclear energy
• potential energy
• radiant energy

Rhymes for energy

• bioenergy

Kids Definition

energy

noun

en·​er·​gy ˈen-ər-jē 

plural energies

1

: power or ability to be active : strength of body or mind to do things or to work

a teacher of great intellectual energy

2

: natural power exerted with force : lively action

work with energy

3

: the capacity (as of heat, light, or running water) for doing work

4

a

: usable power (as heat or electricity)

b

: a source of energy

especially : a resource (as oil) used to provide energy

Medical Definition

energy

noun

en·​er·​gy ˈen-ər-jē 

plural energies

1

: psychic energy

2

: the capacity for doing work