petroleum

noun

pe·​tro·​leum pə-ˈtrō-lē-əm 

-ˈtrōl-yəm

: an oily flammable bituminous liquid that may vary from almost colorless to black, occurs in many places in the upper strata of the earth, is a complex mixture of hydrocarbons with small amounts of other substances, and is prepared for use as gasoline, naphtha, or other products by various refining processes

Examples of petroleum in a Sentence

Recent Examples on the Web

GasBuddy petroleum analyst Patrick De Haan posted to X Thursday that some parts of the country are starting to approach new all-time records for gas prices. —Neal Riley, CBS News, 30 Apr. 2026

The milestone comes as oil prices have surged higher over the past week amid a dual blockade by the United States and Iran of the Strait of Hormuz, the key chokepoint in the region for transiting crude and petroleum-based products out of the Persian Gulf. —Rob Wile, NBC news, 29 Apr. 2026

Gasbuddy petroleum analyst Patrick De Haan had a sobering forecast for Americans. —Jessica Guynn, USA Today, 29 Apr. 2026

With the Strait of Hormuz still impassable and one-fifth of the world’s petroleum still locked up in the Persian Gulf, oil and gas giants have been reaping rewards from the supply crunch, sparking rebukes and criticisms from environmental and advocacy groups in the process. —Tristan Bove, Fortune, 28 Apr. 2026

Word History

Etymology

Middle English, "mineral oil," borrowed from Medieval Latin, "mineral oil, crude oil," from Latin petra "rock" (borrowed from Greek pétra) + oleum "oil" — more at petro-, oil entry 1

First Known Use

15th century, in the meaning defined above

Phrases Containing petroleum

• liquefied petroleum gas
• petroleum jelly

Rhymes for petroleum

• folium
• lolium
• oleum
• scholium
• linoleum
• trifolium
• tetrazolium

Kids Definition

petroleum

noun

pe·​tro·​leum pə-ˈtrō-lē-əm 

-ˈtrōl-yəm

: an oily flammable liquid that may vary from almost colorless to black, is obtained from wells drilled in the ground, and is the source of gasoline, kerosene, fuel oils, and other products

Medical Definition

petroleum

noun

pe·​tro·​leum pə-ˈtrō-lē-əm, -ˈtrōl-yəm 

: an oily flammable bituminous liquid that may vary from almost colorless to black, occurs in many places in the upper strata of the earth, is a complex mixture of hydrocarbons with small amounts of other substances, and is prepared for use as gasoline, naphtha, or other products by various refining processes