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

Strategic petroleum reserves were established to replace barrels lost to disruption.

From The Wall Street Journal • Jun. 2, 2026

The country has diversified its energy sources, including into renewables, and had built up its strategic petroleum reserve to a greater extent than others, giving it some extra cushion.

From Barron's • May 30, 2026

The country has diversified its energy sources, including into renewables, and had built up its strategic petroleum reserve to a greater extent than others, giving it some extra cushion.

From Barron's • May 30, 2026

The energy shipping company’s defensive business model, anchored by long-term LNG and petroleum charters, could also support recurring cash flows and stable dividends amid geopolitical uncertainty, she adds.

From The Wall Street Journal • May 26, 2026

Quickly it was realized that petroleum in volume not only could be used to bind bowels and banish scabby growths but could be refined into lucrative products like paraffin and kerosene.

From "A Walk in the Woods" by Bill Bryson

Related Words

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