View synonyms for fuel


[ fyoo-uhl ]


  1. combustible matter used to maintain fire, as coal, wood, oil, or gas, in order to create heat or power.
  2. something that gives nourishment; food.
  3. an energy source for engines, power plants, or reactors:

    Kerosene is used as jet engine fuel.

  4. something that sustains or encourages; stimulant:

    Our discussion provided him with fuel for debate.

    Synonyms: stimulus, impetus, sustenance, ammunition

verb (used with object)

, fu·eled, fu·el·ing or (especially British) fu·elled, fu·el·ling.
  1. to supply with fuel.

verb (used without object)

, fu·eled, fu·el·ing or (especially British) fu·elled, fu·el·ling.
  1. to obtain or replenish fuel.


/ fjʊəl /


  1. any substance burned as a source of heat or power, such as coal or petrol
    1. the material, containing a fissile substance, such as uranium-235, that produces energy in a nuclear reactor
    2. a substance that releases energy in a fusion reactor
  2. something that nourishes or builds up emotion, action, etc


  1. to supply with or receive fuel


/ fyo̅o̅əl /

  1. A substance that produces useful energy when it undergoes a chemical or nuclear reaction. Fuel such as coal, wood, oil, or gas provides energy when burned. Compounds in the body such as glucose are broken down into simpler compounds to provide energy for metabolic processes. Some radioactive substances, such as plutonium and tritium, provide energy by undergoing nuclear fission or fusion.

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Derived Forms

  • ˈfueller, noun

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Other Words From

  • fuel·er (especially British) fuel·ler noun
  • de·fuel verb (used with object) defueled defueling or (especially British) defuelled defuelling
  • non·fuel adjective
  • un·fueled (especially British) un·fuelled adjective
  • well-fueled (especially British) well-fuelled adjective

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Word History and Origins

Origin of fuel1

First recorded in 1300–50; Middle English feuel, fuel(le), from Old French feuaile, from Vulgar Latin focālia (unrecorded), neuter plural of focālis (unrecorded) “of the hearth, fuel,” from Latin focus “hearth” ( focus ) + -ālis -al 1

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Word History and Origins

Origin of fuel1

C14: from Old French feuaile , from feu fire, ultimately from Latin focus fireplace, hearth

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Idioms and Phrases

see add fuel to the fire .

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Example Sentences

Instead, Johnson and co-founder and CTO Julie Blumreiter have developed a way to modify the internal components of the engine to alter its thermodynamics to be able to quickly ignite and combust decarbonized fuels.

That’s the ongoing power of the fossil fuel industry at work.

From Vox

It’s also risky to do prescribed burns or allow natural fires to rage, since the fuels are so built up in many places, Westerling says.

Even if solar and wind power continue to grow rapidly, they simply can’t displace the vast quantities of fossil fuels used to run industrial processes or generate electricity.

Nikola said Hindenburg took a comment made by an employee of Robert Bosch GmbH, a supplier and investor in the company, out of context and underestimated its capabilities to produce hydrogen for its fuel cell-powered trucks.

From Fortune

But Sanders, a representative of the Northeastern vacation state of Vermont, also opposes fossil fuel development.

Added fuel to the fire, he said—as in, the fire was already burning.

The company also converts the gas into a liquid fuel that can run vehicles in its fleet.

Adding fuel to the fire was an often ugly war of words between Mr. Gelb and the unions, both in the press and on social media.

As they passed the runway, bullets shot up from the tall grass, puncturing a fuel tank.

The hills in sight, however, are very considerably wooded, and wood is apparently the common fuel.

Adequate, of course; no sense in taking chances with lives that cost so much fuel to bring here.

She arrived in Liverpool on the 22d June, having consumed her fuel in ten days.

The mountains are covered with wood fit for fuel, mining, architecture, and machinery.

Sometimes the sheds are built near the woods where fuel can be procured, and in the immediate vicinity of the tobacco field.


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Definitions and idiom definitions from Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.




Fuegianfuel air bomb