nuclear
Americanadjective
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pertaining to or involving atomic weapons.
nuclear war.
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operated or powered by atomic energy.
a nuclear submarine.
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(of a nation or group of nations) having atomic weapons.
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of, relating to, or forming a nucleus.
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of, relating to, or like the nuclear family.
nuclear bonds.
noun
adjective
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of, concerned with, or involving the nucleus of an atom
nuclear fission
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biology of, relating to, or contained within the nucleus of a cell
a nuclear membrane
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of, relating to, forming, or resembling any other kind of nucleus
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of, concerned with, or operated by energy from fission or fusion of atomic nuclei
a nuclear weapon
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involving, concerned with, or possessing nuclear weapons
nuclear war
a nuclear strike
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Relating to or forming a cell nucleus.
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Relating to atomic nuclei.
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Using energy derived from the nuclei of atoms through fission or fusion reactions.
Pronunciation
In pronouncing nuclear, the second and third syllables are most commonly said as , a sequence of sounds that directly reflects the spelled sequence ‑cle·ar. In recent years, a somewhat controversial pronunciation has come to public attention, with these two final syllables said as . Since , the common pronunciation of ‑cle·ar, might also be represented, broadly, as , the pronunciation can be seen as coming from a process of metathesis, in which the and the change places. The resulting pronunciation is reinforced by analogy with such words as molecular, particular, and muscular, and although it occurs with some frequency among highly educated speakers, including scientists, professors, and government officials, it is disapproved of by many.
Other Word Forms
Etymology
Origin of nuclear
Explanation
Nuclear describes something that has to do with the nucleus — the central part — of an atom. If you're a nuclear physicist, you do a lot of work with that part of the atom. Nuclear power, which comes from nuclear fission — the energy released when the nucleus of an atom is split — is a controversial source of renewable energy. The word nuclear is sometimes used broadly to refer to the core of something. Your nuclear family is you, your parents, and your siblings — in a sense, the central part of your world, kind of like the nucleus of an atom.
Vocabulary lists containing nuclear
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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.
Government officials are crafting a regulatory landscape for a commercial nuclear fleet to bring goods across oceans.
From The Wall Street Journal ● Oct. 23, 2026
As the nuclear fuel melted, it combined with zirconium, a highly resistant metal used in the fuel's protective outer layer.
From Science Daily ● Oct. 23, 2026
The country's electricity is generated from a wide range of sources, including renewables such as solar and wind, as well as more traditional gas-fired and nuclear power stations.
From BBC ● Oct. 22, 2026
Blasted into 1.9 billion-year-old stable bedrock in Eurajoki in southwestern Finland, the geological repository will house spent nuclear fuel in holes drilled into the bedrock, where it will remain harmfully radioactive for thousands of years.
From Barron's ● Oct. 22, 2026
In an emergency, the containment should trap gases that might escape from the inner chambers, but we rely on the reactor vessel to keep a nuclear reaction—and the radiation it produces—contained.
From "Meltdown" by Deirdre Langeland
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Get a wordDefinitions 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.
