fuel

American  

[fyoo-uhl] / ˈfyu əl /

noun

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

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verb (used with object)

fueled, fueling, fuelled, fuelling

1. to supply with fuel.

verb (used without object)

fueled, fueling, fuelled, fuelling

1. to obtain or replenish fuel.

fuel British  

/ fjʊəl /

noun

1. any substance burned as a source of heat or power, such as coal or petrol

2. 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

3. something that nourishes or builds up emotion, action, etc

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verb

1. to supply with or receive fuel

fuel Scientific  

/ fyo̅o̅′əl /

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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fuel Idioms  

1. see add fuel to the fire.

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Other Word Forms

• defuel verb (used with object)
• fueler noun
• fueller noun
• nonfuel adjective
• unfueled adjective
• well-fueled adjective

Etymology

Origin of fuel

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” ( see focus) + -ālis -al ¹

Explanation

What do you and your car have in common? You both run on fuel. Whether its gasoline or nutritious food, fuel produces energy to get up and go. Fuel can also act as a verb that has several different meanings, all related to stimulating something or providing energy. Your brother might fuel up on whole-wheat bread with peanut butter a few hours before a big game. A teacher assigns readings to fuel meaningful class discussion. Memories of your mom's delicious dinners might fuel your desire to learn to cook.

Example Sentences

To mitigate the impact of increased fuel prices due to the conflict in Iran, JetBlue said it reduced second-quarter capacity by nearly 1 percentage point versus close-in expectations.

From The Wall Street Journal • Apr. 28, 2026

And, by 1990, with America on the verge of the first Gulf War, jet fuel prices were through the roof.

From Salon • Apr. 28, 2026

She added BP had been "working with customers and governments to get fuel where it's needed, helping minimize disruption and the impact it can have on people's lives".

From BBC • Apr. 28, 2026

On the list of attendees are major fossil fuel producers Canada, Norway and Australia and developing oil giants Nigeria, Angola and Brazil.

From Barron's • Apr. 28, 2026

Operators needed to get water into the fuel pools, but the pools were five stories in the air, and there was no way to access them from below.

From "Meltdown" by Deirdre Langeland

Related Words

• ammunition
• electricity
• food
• gas
• material