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
Derived 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.
Nuclear facilities have also been hit in the war that erupted on February 28.
From Barron's • Jun. 4, 2026
Nuclear power developer Newcleo said Wednesday that it plans to go public through a merger with a blank-check company in a deal valuing it at about $2.4 billion.
From The Wall Street Journal • May 27, 2026
The Nuclear Regulatory Commission approved Aurora’s Principal Design Criteria —a foundational rulebook for the plant’s safety and performance standards—earlier this month.
From Barron's • May 26, 2026
One former member of the Nuclear Regulatory Commission, appointed during the Carter administration, told MarketWatch that he can’t think of an instance in decades with this type of potential for conflicts of interest.
From MarketWatch • May 18, 2026
Nuclear war, according to them, according to the press, was imminent.
From This Side of Wild by Gary Paulsen
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.
