nuclear fusion

American  

[noo-klee-er fyoo-zhuhn, nyoo-] / ˈnu kli ər ˈfyu ʒən, ˈnyu- /

noun

1. fusion.

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nuclear fusion British  

noun

1. Sometimes shortened to: fusion.  a reaction in which two nuclei combine to form a nucleus with the release of energy Compare nuclear fission See also thermonuclear reaction

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fusion, nuclear Cultural  

1. The combining of two small atomic nuclei to form a larger nucleus, sometimes with the release of energy. (Compare nuclear fission.)

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Pronunciation

See nuclear ( def. ).

Discover More

The use of fusion as a controllable energy source on Earth is still in its experimental stages.

The fusion of hydrogen into helium releases huge amounts of energy and is the main energy source of stars, including the sun.

Hydrogen bombs use the energy of fusion.

Etymology

Origin of nuclear fusion

First recorded in 1895–1900

Example Sentences

In 25 years, Mike Bechtel thinks we will have a new source of clean, abundant energy: nuclear fusion.

From The Wall Street Journal • Apr. 6, 2026

However, as nuclear fusion attracts more public and private capital, Bechtel expects researchers to overcome these problems and make fusion a commercially viable source of energy by 2050.

From The Wall Street Journal • Apr. 6, 2026

The instrument is TAE Technologies, a Foothill Ranch-based company working to develop the technology of nuclear fusion as a clean energy source.

From Los Angeles Times • Mar. 3, 2026

These stars could be powered not only by nuclear fusion, but also by energy released when dark matter particles annihilate.

From Science Daily • Jan. 28, 2026

In the process of nuclear fusion, the nuclei of small atoms combine to form larger ones.

From "Fallout: Spies, Superbombs, and the Ultimate Cold War Showdown" by Steve Sheinkin