Origin of pyro

by shortening; cf. -o


  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, H4Sb2O7, pyroarsenic, H4As2O7, and pyrosulfuric, H2S2O7, 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, H2B4O7, and potassium pyrobate, K2B4O7, or pyrosulfuric, H2S2O7, and pyrosulfate, N2S2O7); if the acid ends in -ous, the corresponding salt ends in -ite (pyrophosphorous acid, H4P2O5, potassium pyrophosphite, K4P2O5).
Also pyr-.

Origin of pyro-

< Greek pyro-, combining form of pŷr fire Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for pyro

Historical Examples of pyro

  • Authorities place the solubility of pyro as one part in two of water.


    Henry R. Blaney

  • A small bottle of Pyro is also convenient for one who brings a curling lamp.


    Emily Post

  • It is to him more than to any other, for instance, that is due the first steps in our knowledge of pyro-(or thermo-) electricity.

  • Almost any of the modern developers (pyro excepted) will give good results with bromide paper.

  • The oxides of alkaline metals or their alkaline salts are not the only accelerators susceptible of being used in pyro development.

British Dictionary definitions for pyro


before a vowel pyr-

combining form
  1. denoting fire, heat, or high temperaturepyromania; pyrometer
  2. caused or obtained by fire or heatpyroelectricity
  3. chem
    1. denoting a new substance obtained by heating anotherpyroboric 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- compoundspyro-phosphoric acid
  4. mineralogy
    1. having a property that changes upon the application of heatpyromorphite
    2. having a flame-coloured appearancepyroxylin

Word Origin for pyro-

from Gk pur fire
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for pyro


before vowels pyr-, word-forming element form meaning "fire," from Greek pyro-, combining form of pyr (genitive pyros) "fire, funeral fire," also symbolic of terrible things, rages, "rarely as an image of warmth and comfort" [Liddell & Scott]; see fire (n.). Pyriphlegethon, literally "fire-blazing," was one of the rivers of Hell.

Online Etymology Dictionary, © 2010 Douglas Harper

pyro in Medicine


  1. Fire; heat:pyrophobia.
  2. Relating to the action of fire or heat:pyrolysis.
  3. Fever:pyrogen.
  4. Derived from an acid by the loss of a water molecule:pyrophosphoric acid.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.