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.
Estimates vary on how much Iran’s ability to make a nuclear bomb has been set back, from several months to several years.
From The Wall Street Journal ● Aug. 28, 2026
Dark Stars are hypothetical primordial stars that would receive much of their energy from heating associated with dark matter instead of relying primarily on ordinary nuclear fusion.
From Science Daily ● Aug. 27, 2026
The responsibility unit includes teams that work on testing Google’s AI models for nuclear, biological and chemical risks.
From The Wall Street Journal ● Aug. 26, 2026
These proportions were higher than for other professions including nuclear technologists, who are routinely exposed to radiation from non-cosmic sources yet placed 12th on the list, the authors said.
From BBC ● Aug. 26, 2026
The Georgia Nuclear Aircraft Laboratory ran a 10-million-watt nuclear reactor completely unshielded.
From "Meltdown" by Deirdre Langeland
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.
