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

Israel has already struck and badly damaged the uranium-enrichment facility at Natanz, the Isfahan Nuclear Technology Center, the heavy-water reactor at Arak, and other sites. —David Remnick, New Yorker, 21 June 2025

Heavy water reactor targeted Israeli fighter jets targeted Iran’s Arak heavy water reactor, located about 155 miles southwest of Tehran, on Thursday. —Elena Becatoros, Chicago Tribune, 20 June 2025

Israel's military said its fighter jets targeted the Arak heavy water reactor, some 155 miles southwest of Tehran, to prevent it from being used to produce plutonium. —Arkansas Online, 20 June 2025

Israel, meanwhile, carried out strikes on Iran’s Arak heavy water reactor. —Kristina Karisch, The Hill, 19 June 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)