exothermic

adjective

exo·​ther·​mic ˌek-sō-ˈthər-mik How to pronounce exothermic (audio)
: characterized by or formed with evolution of heat
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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The show is described as covering topics including safety, pressure and force, simple machines, velocity, application of science to everyday life, multiple experimentation and exothermic, external and chemical formula chemical reactions. — Jessi Virtusio, Chicago Tribune, 23 Sep. 2024 Astrobotic has a different concept called the Nighttime Integrated Thermal and Electricity (NITE) system, which could produce power as a byproduct of exothermic chemical reactions. — Stephen Clark, Ars Technica, 4 Apr. 2024

Word History

Etymology

International Scientific Vocabulary

First Known Use

1884, in the meaning defined above

Time Traveler
The first known use of exothermic was in 1884

Rhymes for exothermic

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Browse Nearby Words

exothermal
exothermic
exotic
See all Nearby Words

Cite this Entry

“Exothermic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/exothermic. Accessed 29 Mar. 2025.

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Kids Definition

exothermic

adjective
exo·​ther·​mic ˌek-sō-ˈthər-mik How to pronounce exothermic (audio)
: characterized by or formed by the giving off of heat
an exothermic chemical reaction

Medical Definition

exothermic

adjective
exo·​ther·​mic -ˈthər-mik How to pronounce exothermic (audio)
: characterized by or formed with evolution of heat compare endothermic
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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