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.
“I put $125,000 into my house, and now a nuclear reactor is coming to town,” said Jerel Johnson, an IT professional who planned to retire in Parsons.
From The Wall Street Journal ● Jul. 28, 2026
In an interview with Fox News on Tuesday morning, Trump was asked about reports that Netanyahu planned to present him with intelligence about new activity at Pickaxe Mountain, a suspected underground nuclear site in Iran.
From Los Angeles Times ● Jul. 28, 2026
Japan is haunted by the memory of a massive 9.0-magnitude undersea quake in 2011, which triggered a tsunami that killed or left missing around 18,500 people and wrecked the Fukushima nuclear plant.
From Barron's ● Jul. 28, 2026
In 2011, Torness nuclear power station in East Lothian was even shut down as a precautionary measure due to huge numbers of jellyfish found in sea water entering the plant.
From BBC ● Jul. 28, 2026
“Not unless it was nuclear, which it wasn’t.”
From "Glitch" by Laura Martin
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.
