or ex·o·ther·mal

[ ek-soh-thur-mik ]
/ ˌɛk soʊˈθɜr mɪk /

adjective Chemistry.

noting or pertaining to a chemical change that is accompanied by a liberation of heat (opposed to endothermic).

Origin of exothermic

First recorded in 1880–85; exo- + thermic

Related forms

ex·o·ther·mi·cal·ly, ex·o·ther·mal·ly, adverbex·o·ther·mic·i·ty [ek-soh-ther-mis-i-tee] /ˌɛk soʊ θərˈmɪs ɪ ti/, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for exothermic

British Dictionary definitions for exothermic



/ (ˌɛksəʊˈθɜːmɪk) /


(of a chemical reaction or compound) occurring or formed with the evolution of heatCompare endothermic, exoergic

Derived Forms

exothermically or exothermally, adverb
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

Medicine definitions for exothermic


[ ĕk′sō-thûrmĭk ]


Of or relating to a chemical reaction during which heat is released.
Of or relating to the external warmth of the body.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for exothermic


[ ĕk′sō-thûrmĭk ]

Relating to a chemical reaction that releases heat. Compare endothermic.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.