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variant of petro-1 before a vowel: petrous.
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Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What does petr- mean?

Petr– is a combining form used like a prefix meaning “rock” or “stone.” It is very rarely used in scientific terms.

Petr– 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.

What are variants of petr-?

When combined with words or word elements that begin with certain consonants, petr– becomes petri. Another variant of petr– is petro. Want to know more? Read our Words That Use petri– and petro– articles.

Examples of petr-

One example of the few words that feature the form petr– is petrous, a term from anatomy meaning “noting or pertaining to the hard dense portion of the temporal bone.” Petrous comes from Latin petrōsus, which features the equivalent of petr– in that language.

The petr– part of the word means “rock,” as we know. The suffix ous means “possessing; full of.” Petrous literally translates to “full of rock.”

What are some words that use the combining form petr-?

What are some other forms that petr– may be commonly confused with?

Not every word that begins with the exact letters petro– or petr-, such as petronel or petrel, is necessarily using the combining form petr– to denote “rock.” Learn why petrel is the name of a seabird at our entry for the word.

Break it down!

The term ichor comes from Greek mythology, in which it refers to a magical fluid that flows in the veins of the gods. With this in mind, what smell does petrichor literally refer to?

How to use petr- in a sentence