exothermic

or ex·o·ther·mal

[ ek-soh-thur-mik ]

adjective

, Chemistry.

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

exothermic

/ ˌɛksəʊˈθɜːmɪk /

adjective

1. (of a chemical reaction or compound) occurring or formed with the evolution of heat Compare endothermic exoergic

exothermic

/ ĕk′sō-thûr′mĭk /

1. Relating to a chemical reaction that releases heat.
2. Compare endothermic

Derived Forms

• ˌexoˈthermically, adverb

Other Words From

• exo·thermi·cal·ly exo·thermal·ly adverb
• ex·o·ther·mic·i·ty [ek-soh-ther-, mis, -i-tee], noun

Word History and Origins

Origin of exothermic¹

First recorded in 1880–85; exo- + thermic

Example Sentences

The reaction is "exothermic," meaning it produces heat as well as steam.

From National Geographic Kids

But at a certain point, he explained, those reactions become exothermic — that is, they generate heat themselves — which kicks the reactions into high gear.

From New York Times

Because sea turtles are exothermic, they get their body temperatures from their surroundings, like air or water.

From Washington Post

The injection creates an exothermic reaction that ignites the fuels inside the balls.

From Washington Times

A footnote to the charging document said such explosive material “gives off heat and energy through a rapid exothermic reaction when initiated by heat, shock or friction.”

From Washington Times