nuclear

adjective

nu·​cle·​ar ˈnü-klē-ər How to pronounce nuclear (audio) ˈnyü- How to pronounce nuclear (audio)
 nonstandard  -kyə-lər
1
: of, relating to, or constituting a nucleus
annexation of the suburban fringe by the nuclear metropolisW. H. Wickwar
2
a
: of or relating to the atomic nucleus
nuclear reaction
nuclear physics
b
: used in or produced by a nuclear reaction (such as fission)
nuclear fuel
nuclear waste
nuclear energy
c(1)
: being a weapon whose destructive power derives from an uncontrolled nuclear reaction
(2)
: of, produced by, or involving nuclear weapons
the nuclear age
nuclear war
(3)
: armed with nuclear weapons
nuclear powers
d
: of, relating to, or powered by nuclear energy
a nuclear submarine
the nuclear debate
a nuclear plant
How do you pronounce nuclear?: Usage Guide

Though disapproved of by many, pronunciations ending in \-kyə-lər\ have been found in widespread use among educated speakers including scientists, lawyers, professors, congressmen, U.S. cabinet members, and at least two U.S. presidents and one vice president. While most common in the U.S., these pronunciations have also been heard from British and Canadian speakers.

Phrases
go nuclear
informal
: to become wildly excited or upset : go berserk
To say the crowd went wild is an understatement. The crowd went nuclear. Outside the stadium, cars were overturned and fires were set. We sportswriters huddled inside, fearing for our lives.Tony Kornheiser

Examples of nuclear in a Sentence

Recent Examples on the Web Moreover, many Germans fear Russian retaliation because the country does not have a nuclear deterrent of its own. Joseph De Weck, The Atlantic, 20 Mar. 2024 Ukraine also surrendered its nuclear arsenal in exchange for guarantees, including from Russia, that the country’s territorial sovereignty would be respected. David L. Stern, Washington Post, 20 Mar. 2024 This was code for saying that the United States should destroy its nuclear weapons before Moscow agreed to any inspection regime. Benn Steil, Foreign Affairs, 19 Mar. 2024 Considerable questions remain about how a nuclear deterrence umbrella would work without the U.S. Anna Mulrine Grobe, The Christian Science Monitor, 19 Mar. 2024 The rugged two-square-mile island has hundreds of Cold War-era bunkers and tunnels designed to withstand nuclear attack and has been largely vacant since the end of the Soviet Union. Maggie Haberman, New York Times, 15 Mar. 2024 Prosecutors countered that those records were clearly presidential, not personal, and included top-secret information and documents related to nuclear programs and the military capabilities of the U.S. and foreign countries. Eric Tucker, Fortune, 15 Mar. 2024 Many of the dozens of Godzilla adventures released since then include themes of environmental disaster and Japan’s experience as the only nation to have nuclear weapons deployed against it. Chris Lau, CNN, 12 Mar. 2024 Both hoped that the nascent nuclear technology would remain under global, and peaceful, control. Kc Cole, Smithsonian Magazine, 8 Mar. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'nuclear.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

nucle(us) + -ar

First Known Use

1822, in the meaning defined at sense 1

Time Traveler
The first known use of nuclear was in 1822

Dictionary Entries Near nuclear

Cite this Entry

“Nuclear.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/nuclear. Accessed 29 Mar. 2024.

Kids Definition

nuclear

adjective
nu·​cle·​ar ˈn(y)ü-klē-ər How to pronounce nuclear (audio)
1
: of, relating to, or being a nucleus (as of a cell)
2
: of, relating to, or using the atomic nucleus
nuclear reactions
3
: being or relating to energy or a weapon that involves a nuclear reaction
nuclear energy
a nuclear war
nuclear power plants

Medical Definition

nuclear

adjective
nu·​cle·​ar ˈn(y)ü-klē-ər How to pronounce nuclear (audio)
1
: of, relating to, or constituting a nucleus
2
: of, relating to, or utilizing the atomic nucleus, atomic energy, the atomic bomb, or atomic power
Last Updated: - Updated example sentences
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