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

With September finally here, the yellow, orange and red hues of fall foliage will soon make an appearance, signalling the coming of the autumn and trees preserving their energy each year. —Saleen Martin, USA Today, 14 Sep. 2025

High-speed charging generates substantial thermal energy, which can accelerate cell degradation, reduce the battery’s overall lifespan, and in rare cases, lead to safety issues like thermal runaway. —Aman Tripathi, Interesting Engineering, 14 Sep. 2025

The energy and adrenaline is so extreme. —Sean Clancy, Arkansas Online, 14 Sep. 2025

The frenetic energy carried on into Saturday night, the climax of the week, the event whence Burning Man gets its name, when the entire city gathers to watch a towering effigy go up in flames. —Denver Nicks, Rolling Stone, 14 Sep. 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