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

The reactor design was one of three early-stage concept projects selected for support under the US Department of Energy’s Advanced Reactor Demonstration Program. —Aman Tripathi, Interesting Engineering, 29 Nov. 2025

For this film coating, methane and hydrogen gases were fed into a reactor chamber that contained silicon wafers spin-coated with a nanodiamond solution. —Abhimanyu Ghoshal, New Atlas, 27 Nov. 2025

Russia weighs nuclear power project in Kyrgyzstan Russia is considering building Kyrgyzstan’s first nuclear power plant using small modular reactor technology, President Vladimir Putin announced after talks in Bishkek. —Matthew Robinson, MSNBC Newsweek, 26 Nov. 2025

The 835-megawatt reactor can power the equivalent of approximately 800,000 homes, the Department of Energy said. —CBS News, 19 Nov. 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)