[floh-jis-ton, -tuh n]
See more synonyms for phlogiston on

Origin of phlogiston

1720–30; < New Latin: inflammability, noun use of Greek phlogistón, neuter of phlogistós inflammable, burnt up; see phlogistic Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for phlogiston

Historical Examples of phlogiston

  • He thought they were "compounded" of a certain earth, or calx, and phlogiston.

    Priestley in America

    Edgar F. Smith

  • It was phlogiston and that only which occasioned the electric current.

    Priestley in America

    Edgar F. Smith

  • I should have sent you my Defence of Phlogiston, but that I presume you have seen it.

    Priestley in America

    Edgar F. Smith

  • Coal, for example, was thought to be very rich in phlogiston.

  • "Phlogiston" and "vortices" had their day and are forgotten.


    William Graham Sumner

British Dictionary definitions for phlogiston


  1. chem a hypothetical substance formerly thought to be present in all combustible materials and to be released during burning

Word Origin for phlogiston

C18: via New Latin from Greek, from phlogizein to set alight; related to phlegein to burn
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 phlogiston

1730, hypothetical inflammatory principle, formerly believed to exist in all combustible matter, from Modern Latin (1702), from Greek phlogiston (1610s in this sense), neuter of phlogistos "burnt up, inflammable," from phlogizein "to set on fire, burn," from phlox (genitive phlogos) "flame, blaze" (see bleach (v.)). Theory propounded by Stahl (1702), denied by Lavoisier (1775), defended by Priestley but generally abandoned by 1800. Related: Phlogistic; phlogisticated.

Online Etymology Dictionary, © 2010 Douglas Harper

phlogiston in Science


  1. A hypothetical colorless, odorless, weightless substance once believed to be the combustible part of all flammable substances and to be given off as flame during burning. In the 18th century, Antoine Lavoisier proved that phlogiston does not exist. See Note at Lavoisier.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.