petro-

¹ American  

1. a combining form meaning “rock,” “stone,” used in the formation of compound words.

   petrology.

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petro- ² American  

1. a combining form meaning “petroleum,” “the extraction and export of petroleum,” used in the formation of compound words.

   petrochemistry; petropower.

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petro ³ American  

[pe-troh] / ˈpɛ troʊ /

adjective

1. of or relating to petroleum or the petroleum industry.

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noun

1. Canadian.  the federally owned petroleum industry.

petro- British  

combining form

1. indicating stone or rock

   petrology

2. indicating petroleum, its products, etc

   petrochemical

3. of or relating to a petroleum-producing country

   petrostate

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Usage

What does petro- mean? Petro- is a combining form used like a prefix that has two distinct senses.The first of these senses is “rock” or "stone," and this form of petro- is occasionally used in a variety of scientific and technical terms. Petro- comes from Greek pétra, meaning “rock.” Two Latin translations of pétra are lapis and saxum, both meaning “stone,” which are the roots of terms such as lapis lazuli and saxifrage, respectively. To learn more, check out our entries for both words.The second of these senses is “petroleum,” and this form of petro- is occasionally used in a variety of technical terms. Petro- is an abbreviation of the word petroleum, from the Medieval Latin word for "rock oil; the -oleum element means "oil" in Latin. Find out more about the word petroleum at our entry for the word.What are variants of petro- with the sense “rock”?Petri- is a variant of petro-, which exchanges its -o- for an -i- when combined with words or word elements beginning with certain consonants. Another variant for petro- in this sense is petr-, which loses its -o- combined with words or word elements beginning with vowels. Want to know more? Read our Words That Use articles for petri- and petr-.Not every word that begins with the exact letters petro- or petr-, such as petronel or petrel, is necessarily using the combining form petro- to denote “rock” or "petroleum.” Learn why petrel is the name of a seabird at our entry for the word.

Etymology

Origin of petro-¹

< Greek, combining form of pétra rock, pétros a stone

Origin of petro-¹

Extracted from petroleum

Origin of petro¹

First recorded in 1970–75; independent use of petro- ²

Example Sentences

The group is in peace talks with the left-wing government of President Gustavo Petro.

From Barron's

Petro, himself a former leftist guerrilla, has cast doubt on the veracity of the Caracol revelations.

From Barron's

Defense Minister Pedro Sanchez ordered the investigation after the Caracol report, which detailed documents that showed contact in early 2024 between a guerrilla group led by Alexander Diaz and Juan Miguel Huertas, a retired general whom Petro later appointed as the army’s chief of personnel.

From The Wall Street Journal

Petro has condemned the strikes as extrajudicial killings.

From The Wall Street Journal

The military stopped Diaz at a military checkpoint in July 2024, but Colombia’s attorney general ordered his release, saying the stocky commander couldn’t be prosecuted because was an important negotiator for Petro’s so-called Total Peace plan, a flagship effort to broker peace and disarmament pacts with Colombia’s myriad drug-fueled insurgent groups.

From The Wall Street Journal