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

Fusion machines do not rely on the same process as traditional nuclear fission reactors and have different fuel cycles, waste streams, and safety characteristics, officials said. —Stephen Underwood, Hartford Courant, 3 May 2026

The company has also inked agreements with META for several more reactors to power the tech company's data centers specifically. —Kirk Siegler, NPR, 2 May 2026

Alexander Ugryumov, Senior Vice President for Research and Development at TVEL, stated that burning minor actinides in a commercial reactor is a long-term strategy rather than a single experiment. —Aman Tripathi, Interesting Engineering, 1 May 2026

During a late-night safety test, the power plant’s Number 4 reactor exploded, tearing through the building and sending a column of radioactive material into the sky. —Benjamin MacK-Jackson, The Orlando Sentinel, 30 Apr. 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)