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 package also contains funding for building projects around the state, including $50 million for a nuclear research reactor used for cancer treatments at the University of Missouri. —Arkansas Online, 6 June 2025

The kicker: this reactor design originated in the US. —Wal Van Lierop, Forbes.com, 5 June 2025

NuScale will benefit if its small modular reactor design clears the NRC, Goldman's Lee said. —Spencer Kimball, CNBC, 27 May 2025

In keeping with plans for mass production of modular reactors, the order also calls for a single certification process for these designs, focusing solely on site differences once the general reactor design is accepted as safe. —ArsTechnica, 27 May 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)