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 Vogtle project was a nearly $35 billion boondoggle, plagued by massive cost overruns, to build Westinghouse’s next-generation, light-water AP1000 reactors. —Jordan Blum, Fortune, 13 June 2026

Recently scientists have been experimenting with tungsten for a different purpose—as shielding nuclear fusion reactors. —Ari Sen, Scientific American, 13 June 2026

These modular reactors can eventually be connected directly to active factory smokestacks and local agricultural biorefineries. —Mrigakshi Dixit, Interesting Engineering, 12 June 2026

Even excellent operators cannot reliably hold those relationships in their heads in real time, especially across a fleet of reactors running different products at different scales. —Hamid Noori, Forbes.com, 28 May 2026

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

• acter
• actor
• factor
• tractor
• attractor
• cofactor
• compactor
• contactor
• contractor
• distractor
• extractor
• impactor

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)