petroleum

American  

[puh-troh-lee-uhm] / pəˈtroʊ li əm /

noun

1. an oily, thick, flammable, usually dark-colored liquid that is a form of bitumen or a mixture of various hydrocarbons, occurring naturally in various parts of the world and commonly obtained by drilling: used in a natural or refined state as fuel, or separated by distillation into gasoline, naphtha, benzene, kerosene, paraffin, etc.

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petroleum British  

/ pəˈtrəʊlɪəm /

noun

1. a dark-coloured thick flammable crude oil occurring in sedimentary rocks around the Persian Gulf, in parts of North and South America, and below the North Sea, consisting mainly of hydrocarbons. Fractional distillation separates the crude oil into petrol, paraffin, diesel oil, lubricating oil, etc. Fuel oil, paraffin wax, asphalt, and carbon black are extracted from the residue

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petroleum Scientific  

/ pə-trō′lē-əm /

1. A thick, flammable, yellow-to-black mixture of gaseous, liquid, and solid hydrocarbons that occurs naturally beneath the Earth's surface. It can be separated into fractions including natural gas, gasoline, naphtha, kerosene, paraffin wax, asphalt, and fuel and lubricating oils, and is used as raw material for a wide variety of derivative products. It is believed to originate from the accumulated remains of fossil plants and animals, especially in shallow marine environments.

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Other Word Forms

Derived Forms

• petroleous
  adjective

Etymology

Origin of petroleum

1520–30; < Medieval Latin: literally, rock oil, equivalent to Latin petr ( a ) rock (< Greek pétra ) + oleum oil

Compare meaning

How does petroleum compare to similar and commonly confused words? Explore the most common comparisons:

• petrolatum vs. petroleum

Explanation

Petroleum is oil — a fossil fuel that powers many vehicles and other machinery. Petroleum is a fancy, technical word for something you've probably heard of: oil, an energy source. Petroleum is also known as crude, crude oil, fossil oil, and rock oil. A lot of petroleum is found in the Middle East, and people are always looking for new sources of petroleum. You have to drill for petroleum, because it's deep inside the Earth. There’s a limited amount of petroleum, so many people worry that we're going to use it all up.

Example Sentences

In other words, the reserves his company and others have been tapping — including the U.S. strategic petroleum reserve, which is supposed to be used only for global emergencies — are about to run out.

From Salon • Jun. 7, 2026

Nature chose its location some 60,000 years ago, when crude petroleum that formed millions of years earlier began seeping to the surface.

From Los Angeles Times • Jun. 6, 2026

The U.S. is a net exporter of petroleum products, which cushions the hit to consumers from higher fuel prices.

From The Wall Street Journal • Jun. 5, 2026

And in India, which depends on liquefied petroleum gas for cooking, there’s been a huge surge of interest in electric induction stoves.

From Barron's • May 28, 2026

The food in our organic meal had floated to us on a sea of petroleum just as surely as the corn-based meal we’d had from McDonald’s.

From "The Omnivore's Dilemma" by Michael Pollan

Related Words

• crude oil
• fossil fuel
• fuel
• gas
• gasoline
• kerosene
• natural gas
• petrol