reactor

noun

re·​ac·​tor rē-ˈak-tər 

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

Built to house the workers at the nearby Chernobyl nuclear power plant and their families, Pripyat had been abandoned in the aftermath of the April 26, 1986, explosion that destroyed one of the reactors and sent radiation spewing across Europe. —Richard Sutcliffe, New York Times, 26 Apr. 2025

Oklo says its reactors, called Aurora, have smaller and simpler designs that will range from 75 megawatts to as much as 100 megawatts or more. —Pippa Stevens, CNBC, 22 Apr. 2025

Our longstanding game plan is to build at least 19 more reactors, meaning that tens of billions of dollars in potential contracts are up for grabs. —Josh Hammer, MSNBC Newsweek, 21 Apr. 2025

National laboratories have consistently produced breakthroughs in energy technology; labs are now working on nuclear-fusion reactors that could help power the future. —The New Yorker, New Yorker, 21 Apr. 2025

Word History

First Known Use

1890, in the meaning defined at sense 1

Phrases Containing reactor

• atomic reactor
• hyper-reactor
• nuclear reactor

Rhymes for reactor

• attractor
• cofactor
• compactor
• contactor
• contractor
• distractor
• extractor
• impactor
• protractor
• redactor
• refractor
• retractor

Kids Definition

reactor

noun

re·​ac·​tor rē-ˈak-tər 

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 

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)