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

This includes cars, aircraft, electronics, petroleum products, textiles, machinery, computers, pharmaceutical products and steel, to name just a few, which will now be bought in smaller quantities from the United States. —Tom Zirpoli, Baltimore Sun, 3 Feb. 2026

Patrick De Haan, head of petroleum analysis at GasBuddy, gave a mixed picture of whether gas prices nationally would rise or fall, pointing out that oil prices jumped to their highest level in months amid geopolitical tensions. —Frank Witsil, Freep.com, 2 Feb. 2026

The raid convulsed that country, and the effects still ripple through this oil-rich city, home to major petroleum companies as well as a large Venezuelan community. —Frank Langfitt, NPR, 1 Feb. 2026

The process, called extraction, is borrowed partly from food science and partly from petroleum refining and partly from the fluid mechanics of HVAC engineering. —Scott Eden, Rolling Stone, 1 Feb. 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