petro-

¹

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

   petrology.

petro-

²

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

   petrochemistry; petropower.

petro

³

[pe-troh]

adjective

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

noun

1. Canadian.,  the federally owned petroleum industry.

petro-

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

Word History and Origins

Origin of petro-¹

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

Origin of petro-²

Extracted from petroleum

Origin of petro-³

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

Word History and Origins

Origin of petro-¹

from Greek petra rock or petros stone

Example Sentences

Colombia's President Gustavo Petro has criticised the strikes, saying Colombian citizens were on board the boat hit on 15 September, and later claiming Mr Carranza was among those killed.

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Responding to his first statement about Colombian citizens being killed, the White House said it looked forward to President Petro "publicly retracting his baseless and reprehensible statement".

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A US lawyer working for some of Mr Carranza's family, Daniel Kovalik, who also works for President Petro, says Mr Carranza's wife and older daughter recognised his boat from the US-released footage of the strike.

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"President Petro Poroshenko at that time did not dare to sanction the channels," said Shekhovstov.

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"President Gustavo Petro should never have done this. Knowing there were minors, he nevertheless authorized" the bombing, the young woman added.

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When To Use

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.