nuclear energy
Americannoun
noun
-
The energy released by the nucleus of an atom as the result of nuclear fission, nuclear fusion, or radioactive decay. The amount of energy released by the nuclear fission of a given mass of uranium is about 2,500,000 times greater than that released by the combustion of an equal mass of carbon. And the amount of energy released by the nuclear fusion of a given mass of deuterium is about 400 times greater that that released by the nuclear fission of an equal mass of uranium.
-
Also called atomic energy
-
Electricity generated by a nuclear reactor.
Pronunciation
See nuclear ( def. ).
Etymology
Origin of nuclear energy
First recorded in 1925–30
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
This resistance to environmental disturbances makes nuclear energy transitions especially promising for ultra-precise timekeeping.
From Science Daily ● Oct. 11, 2026
Regardless, investors likely haven’t seen the last big deal, and that’s driven meaningful recent gains for stocks tied to nuclear energy.
From MarketWatch ● Oct. 8, 2026
Amazon just made a new nuclear energy investment that could expand the capacity of America’s reactor fleet.
From Barron's ● Sep. 30, 2026
Roughly 50 companies are working on the small reactors, mostly in the U.S., said Adam Stein, director of nuclear energy and innovation at the Breakthrough Institute.
From Los Angeles Times ● Aug. 28, 2026
“It may be that the day of useful nuclear energy is not so far distant after all,” he wrote to his fellow cyclotron builder Alexander Allen.
From "Big Science" by Michael Hiltzik
![]()
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.