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

Construction of the nuclear island is slated to begin next year, with the first reactor targeted for commercial operation in 2032. —Aman Tripathi, Interesting Engineering, 3 Oct. 2025

The company's technology is now embedded at dozens of reactors across the country. —Sasha Hupka, AZCentral.com, 3 Oct. 2025

If proven out, OpenStar could build fusion reactors that are smaller, cheaper, faster to build, and easier to maintain and operate, Mataira said. —Jordan Blum, Fortune, 2 Oct. 2025

But others, especially in the small modular reactor (SMR) field, are now making forays into the public market, creating new opportunities and risks for retail investors. —Tim McDonnell, semafor.com, 2 Oct. 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)