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 energy giant intends to remain closely involved in the development phase to evaluate how these reactors can benefit its own upstream and downstream operations. —Aman Tripathi, Interesting Engineering, 20 Dec. 2025

The agency has also been developing a potential fission reactor for use on the moon for several years now, with the goal of deploying it in the early 2030s. —Mike Wall, Space.com, 19 Dec. 2025

The reactors are suitable for use on army bases, remote communities, disaster areas, and energy-hungry data centers. —Abhimanyu Ghoshal, New Atlas, 18 Dec. 2025

As a stopgap, Weinberg’s team had to repeatedly off-gas the reactor compartment, bathing a nearby forest in radioactive xenon and iodine. —Colin Jones, New Yorker, 18 Dec. 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)