reactor

noun

re·​ac·​tor rē-ˈak-tər How to pronounce reactor (audio)
1
: one that reacts
2
: a device (such as a coil, winding, or conductor of small resistance) used to introduce reactance into an alternating-current circuit
3
a
: a vat for an industrial chemical reaction
b
: a device for the controlled release of nuclear energy (as for producing heat)

Examples of reactor 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.
Despite breaking ground on its first reactor nearly four decades after the U.S. pioneered the tech, China’s now building far more fission power plants than any other country. — Katie Tarasov, CNBC, 16 Mar. 2025 The small modular reactor startup X-energy's work with Amazon to deploy the technology won't be its only tie-up with a major tech player, CEO Clay Sell said. — Ben Geman, Axios, 14 Mar. 2025 The company says this will lead to a cost-effective method for producing electricity when its finished reactor is up and running. — New Atlas, 12 Mar. 2025 That's the nuclear power plant in Pennsylvania whose reactor #2 had a partial meltdown in 1979. — David Pogue, CBS News, 9 Mar. 2025 See All Example Sentences for reactor

Word History

First Known Use

1890, in the meaning defined at sense 1

Time Traveler
The first known use of reactor was in 1890

Phrases Containing reactor

Rhymes for reactor

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Browse Nearby Words

reactor
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Cite this Entry

“Reactor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/reactor. Accessed 24 Mar. 2025.

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Kids Definition

reactor

noun
re·​ac·​tor rē-ˈak-tər How to pronounce reactor (audio)
1
: one that reacts
2
: a device for the controlled release of nuclear energy (as for producing heat)

Medical Definition

reactor

noun
re·​ac·​tor rē-ˈak-tər How to pronounce reactor (audio)
1
: one that reacts: as
a
: a chemical reagent
b
: an individual reacting to a stimulus
c
: an individual reacting positively to a foreign substance (as in a test for disease)
reactors to tuberculin
2
a
: a piece of equipment in which a chemical reaction and especially an industrial chemical reaction is carried out
b
: a device for the controlled release of nuclear energy (as for producing heat)

More from Merriam-Webster on reactor

Nglish: Translation of reactor for Spanish Speakers

Britannica.com: Encyclopedia article about reactor

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