oil

American  

[oil] / ɔɪl /

noun

1. any of a large class of substances typically unctuous, viscous, combustible, liquid at ordinary temperatures, and soluble in ether or alcohol but not in water: used for anointing, perfuming, lubricating, illuminating, heating, etc.

2. a substance of this or similar consistency.

3. refined or crude petroleum.

4. Painting.

   1. oil color.

   2. oil painting.

5. Informal. unctuous hypocrisy; flattery.

6. an oilskin garment.

7. Australian and New Zealand Slang. facts or news; information.

   good oil.

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verb (used with object)

1. to smear, lubricate, or supply with oil.

2. to bribe.

3. to make unctuous or smooth.

   to oil his words.

4. to convert into oil by melting, as butter.

adjective

1. pertaining to or resembling oil.

2. using oil, especially as a fuel.

   an oil furnace.

3. concerned with the production or use of oil.

   an offshore oil rig.

4. made with oil.

5. obtained from oil.

idioms

1. pour oil on troubled waters, to attempt to calm a difficult or tense situation, as an argument.

2. strike oil,

   1. to discover oil, especially to bring in a well.

   2. to have good luck, especially financially; make an important and valuable discovery.

      They struck oil only after years of market research.

oil British  

/ ɔɪl /

noun

1. any of a number of viscous liquids with a smooth sticky feel. They are usually flammable, insoluble in water, soluble in organic solvents, and are obtained from plants and animals, from mineral deposits, and by synthesis. They are used as lubricants, fuels, perfumes, foodstuffs, and raw materials for chemicals See also essential oil fixed oil

2. 1. another name for petroleum

   2. ( as modifier )

      an oil engine

      an oil rig

3. 1. Also called: lubricating oil.  any of a number of substances usually derived from petroleum and used for lubrication

   2. ( in combination )

      an oilcan

      an oilstone

   3. ( as modifier )

      an oil pump

4. Also called: fuel oil.  a petroleum product used as a fuel in domestic heating, industrial furnaces, marine engines, etc

5. 1. paraffin, esp when used as a domestic fuel

   2. ( as modifier )

      an oil lamp

      an oil stove

6. any substance of a consistency resembling that of oil

   oil of vitriol

7. the solvent, usually linseed oil, with which pigments are mixed to make artists' paints

8. 1. (often plural) oil colour or paint

   2. ( as modifier )

      an oil painting

9. an oil painting

10. slang facts or news

11. 1. to discover petroleum while drilling for it

    2. informal to become very rich or successful

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verb

1. to lubricate, smear, polish, etc, with oil or an oily substance

2. informal to bribe (esp in the phrase oil someone's palm )

3. to make things run smoothly

4. See well-oiled

oil Scientific  

/ oil /

1. Any of a large class of viscous liquids that are typically very slippery and greasy. Oils are composed mostly of glycerides. They are flammable, do not mix with water, and include animal and vegetable fats as well as substances of mineral or synthetic origin. They are used in food, soap, and candles, and make good lubricants and fuels.

2. See essential oil mineral oil petroleum

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oil More Idioms  

1. see banana oil; burn the midnight oil; grease (oil) someone's palm; grease (oil) the wheels; pour oil on troubled waters; strike it rich (oil).

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Other Word Forms

• oil-like adjective
• oilless adjective
• oillessness noun
• oillike adjective
• reoil verb
• self-oiling adjective
• unoiling adjective

Etymology

Origin of oil

1125–75; Middle English olie, oile < Old French < Latin oleum, olīvum (olive) oil < *oleivum ( cf. Deus) < dialectal Greek *élaiwon ( Attic élaion ), derivative of *elaíwā olive

Explanation

Oil is a liquid fat or fuel. You might dress your salad with olive oil and use motor oil in your car's engine; just don't confuse the two! There's the oil you put in your car or use to oil a rusty lock — then there's the oil you heat to stir fry vegetables or whisk with vinegar to make salad dressing. Chemically, these oils have a lot in common, from their tendency to avoid water to their slipperiness to the ease with which they catch on fire. Still, you'd never want to toss a bowl of spaghetti with motor oil — stick to olive oil instead.

Example Sentences

“Markets ‘moved on’ from the war and oil prices when gas prices stopped going up,” Esther Sholes, senior macro analyst at Take Profit Trader, and former portfolio manager at Millennium Investment Management, told MarketWatch.

From MarketWatch • Apr. 24, 2026

"For natural rubber gloves, input costs have risen by approximately 30 percent, as natural rubber is a traded commodity which is impacted by the uptrend in crude oil prices," the company added.

From Barron's • Apr. 24, 2026

“Depending when this ends, it’s going to take months to recover,” says Angie Gildea, global head of oil and gas at KPMG.

From The Wall Street Journal • Apr. 24, 2026

“There’s a huge black cloud over the sea for the World Cup and the travel slump that we’re seeing is all linked to this oil shortage.”

From Los Angeles Times • Apr. 24, 2026

He took down from the wall the oil painting of the man in uniform.

From "Impossible Creatures" by Katherine Rundell

Related Words

• coat
• grease