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• pyro
  pyro

  noun

  a pyromaniac.
• pyro-
  pyro-

  a combining form meaning “fire,” “heat,” “high temperature,” used in the formation of compound words.

pyro

¹ American  

[pahy-roh] / ˈpaɪ roʊ /

noun

Informal.

pyros plural

1. a pyromaniac.

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pyro- ² American  

1. a combining form meaning “fire,” “heat,” “high temperature,” used in the formation of compound words.

   pyrogen; pyrolusite; pyromancy.

2. Chemistry. a combining form used in the names of inorganic acids, indicating that the acid's water content is intermediate between that of the corresponding ortho- (more water) and meta- (least water) acids (pyroantimonic, H 4 Sb 2 O 7 , pyroarsenic, H 4 As 2 O 7 , and pyrosulfuric, H 2 S 2 O 7 ,acids ). The combining form is also used in the names of the salts of these acids. If the acid ends in -ic, the corresponding salt ends in -ate (pyroboric acid, H 2 B 4 O 7 , and potassium pyrobate, K 2 B 4 O 7 , or pyrosulfuric, H 2 S 2 O 7 , and pyrosulfate, N 2 S 2 O7 ); if the acid ends in -ous, the corresponding salt ends in -ite (pyrophosphorous acid, H 4 P 2 O 5 , potassium pyrophosphite, K 4 P 2 O5 ).

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pyro- British  

combining form

1. denoting fire, heat, or high temperature

   pyromania

   pyrometer

2. caused or obtained by fire or heat

   pyroelectricity

3. chem

   1. denoting a new substance obtained by heating another

      pyroboric acid is obtained by heating boric acid

   2. denoting an acid or salt with a water content intermediate between that of the ortho- and meta- compounds

      pyro-phosphoric acid

4. mineralogy

   1. having a property that changes upon the application of heat

      pyromorphite

   2. having a flame-coloured appearance

      pyroxylin

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Usage

What does pyro- mean? Pyro- is a combining form used like a prefix that has two distinct senses. The first of these senses is “fire,” "heat," or "high temperature," and this form of pyro- is occasionally used in a variety of scientific and technical terms. The second of these senses is used in terms from chemistry to mean “inorganic acids” or "the salt of inorganic acids."Pyro- in both of these senses comes from Greek pŷr, meaning “fire.” The Latin translations of pŷr are ignis and incendium, both of which also mean “fire” and are the sources of terms such as ignite and incendiary. To learn more, check out our entries for both words. What are variants of pyro-?When combined with words or word elements that begin with a vowel, pyro- becomes pyr-, as in pyric. Want to know more? Read our Words That Use article on pyr-.

Other Word Forms

Noun Inflected Forms

• pyros
  plural

Etymology

Origin of pyro¹

By shortening; cf. -o

Origin of pyro-²

< Greek pyro-, combining form of pŷr fire

Example Sentences

See Examples For:

pyro pyro- pyros

An elaborate show featuring poetry, pyro and Frederic Michalak will precede the match.

From BBC ● Mar. 14, 2026

Pre-match, nobody in the ground could have said they weren't ready to run on that pitch and do the job themselves when one of Hampden's great renditions of Flower of Scotland followed a pyro show.

From BBC ● Nov. 18, 2025

It’s like half the normal film, and then they’ve integrated pyro and stuff happening live on a stage.

From Los Angeles Times ● Jul. 10, 2025

For the fiery headbanger, Post unleashed a string of guttural screams and blew half his pyro budget for his biggest rock-star moment of the night.

From Seattle Times ● Nov. 6, 2022

The pyro is the developing agent, or that which gives the required strength or density, while the alkaline solution, containing the sulphite of soda, prevents the staining of the negative and preserves the pyro.

From Harper's Round Table, July 30, 1895 by Various

But enough of these follies: ‘Necro-, pyro-, geo-, hydro-, cheiro-, coscinomancy, With other vain and superstitious sciences.’

From Witch, Warlock, and Magician Historical Sketches of Magic and Witchcraft in England and Scotland by Adams, W. H. Davenport (William Henry Davenport)

“For the really small ones it’s dark on that stage, there’s dry ice and pyros and it can be a bit frightening,’’ says Joseph.

From Newsweek

Seconds later, preignition pyros fired, igniting the main engines, and the MAV lurched upward.

From "The Martian" by Andy Weir

"I have tested Merck's pyro carefully in comparison with the other pyros at present on the market, and I find that it is superior to any and all of them."

From Photogravure by Blaney, Henry R.

When electricity develops under the influence of heat, or is in any way connected with a rising or falling of temperature in a body, it is called "pyro-electricity," from the Greek word "pyros," fire.

From The Chemistry, Properties and Tests of Precious Stones by Mastin, John

He is a monster whose destiny is providentially proclaimed by his name, for it is derived from the Greek word, pyros, which means fire.

From Penguin Island by France, Anatole