exo·​ther·​mic | \ ˌek-sō-ˈthər-mik How to pronounce exothermic (audio) \

Definition of exothermic

: characterized by or formed with evolution of heat

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Other Words from exothermic

exothermically \ ˌek-​sō-​ˈthər-​mi-​k(ə-​)lē How to pronounce exothermic (audio) \ adverb
exothermicity \ ˌek-​sō-​ˌthər-​ˈmi-​sə-​tē How to pronounce exothermic (audio) \ noun

Examples of exothermic in a Sentence

Recent Examples on the Web Be aware that lye is exothermic and will generate a lot of heat (about 200 degrees) when added to the water. New York Times, 13 May 2021 The injection creates an exothermic reaction that ignites the fuels inside the balls. Andre Toran, The Courier-Journal, 31 Mar. 2021 Once started, this exothermic process causes heat (around 500℉), and oxygen is produced. John Cox, USA TODAY, 4 Dec. 2020 In this case, the students hope to combine concepts similar to those found in instant snow and hand warmers to create an exothermic reaction. Elizabeth Depompei, Indianapolis Star, 15 Jan. 2020 To put it in the language of chemistry, Schultz, a chemist, is seeking to catalyze an exothermic reaction. Bradley J. Fikes, sandiegouniontribune.com, 25 June 2018 In modern rockets, such as the Space X Falcon 9 or the Saturn V, the propulsion system is powered by a fast, exothermic reaction between a liquid fuel (usually hydrogen, methane or hydrazine) and oxidizer (usually oxygen or nitrogen tetroxide). Renee Morad, Scientific American, 7 Sep. 2017 For an exothermic reaction, which of the following best describes the effect of increasing the temperature on the forward and reverse reactions? Donna Vickroy, Daily Southtown, 5 Apr. 2018 Soon, however, the ACA will erupt into an exothermic death trap like ammonium nitrate combined with fuel oil. Katy Waldman, Slate Magazine, 27 Mar. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'exothermic.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of exothermic

1884, in the meaning defined above

History and Etymology for exothermic

International Scientific Vocabulary

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Time Traveler for exothermic

Time Traveler

The first known use of exothermic was in 1884

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Cite this Entry

“Exothermic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/exothermic. Accessed 29 Jul. 2021.

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More Definitions for exothermic


exo·​ther·​mic | \ -ˈthər-mik How to pronounce exothermic (audio) \

Medical Definition of exothermic

: characterized by or formed with evolution of heat — compare endothermic

Other Words from exothermic

exothermically \ -​mi-​k(ə-​)lē How to pronounce exothermic (audio) \ adverb
exothermicity \ -​ˌthər-​ˈmis-​ət-​ē How to pronounce exothermic (audio) \ noun, plural exothermicities


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