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

As fuel prices soar, major economies including Brazil, India, Indonesia, and the US are advancing policies to expand biofuel mandates in petroleum products. — Chloé Farand, semafor.com, 25 Sep. 2026

Biodiesel, which is produced from sources such as vegetables rather than petroleum, exists, but its share of the diesel market is far too small to influence overall pricing, Farrauto says. — Adam Kovac, Scientific American, 24 Sep. 2026

Gasoline prices could rise toward record levels if an export ban is implemented, said Patrick De Haan, head of petroleum analysis at GasBuddy, in a social media post. — Spencer Kimball, CNBC, 23 Sep. 2026

Ammonia manufacturing and petroleum refining require continuous, high-volume hydrogen feedstocks alongside steady heat. — Aman Tripathi, Interesting Engineering, 23 Sep. 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