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

go nuclear
: 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 That brings us nicely to nuclear testing, also operating on a fallacy that there are no people or animals in the Nevada or Australian deserts. Matt Simon, WIRED, 27 Nov. 2023 First developed for American nuclear missiles in the early 1950s, synthetic aperture radar is an instrument that uses short antennas emitting a sequence of radar waves combined—ergo, synthetic—in order to simulate a much larger antenna. IEEE Spectrum, 24 Nov. 2023 Regrettably, today, even as U.S. and Chinese warships and aircraft risk clashes in the western Pacific, in particular near the Taiwan Strait, and as U.S. and Chinese strategic nuclear missiles target population centers, the two countries lack robust crisis prevention and management mechanisms. Wang Jisi, Foreign Affairs, 23 Nov. 2023 Amichai Eliyahu, the Jerusalem affairs and heritage minister, suggested dropping a nuclear bomb on Gaza. Alexander Smith, NBC News, 22 Nov. 2023 And last week, officials from China and the United States discussed a related issue: potential limits on the use of A.I. in decisions about deploying nuclear weapons. Eric Lipton, New York Times, 21 Nov. 2023 Thus, one of the most efficient ingredients for making a nuclear weapon was born. Sarah Scoles, Scientific American, 14 Nov. 2023 That’s because, as is the case at nuclear plants across the country, the federal government has not found a permanent repository to store the roughly 89,000 metric tons of waste that has built up over the decades at commercial nuclear power plants in 35 states. Rob Nikolewski, San Diego Union-Tribune, 16 Nov. 2023 Pacific Gas & Electric took another step toward keeping the Diablo Canyon nuclear plant operating past its 2025 shutdown date, submitting a license renewal application to the federal government. Sammy Roth, Los Angeles Times, 14 Nov. 2023 See More

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


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.” Dictionary, Merriam-Webster, Accessed 11 Dec. 2023.

Kids Definition


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

Medical Definition


nu·​cle·​ar ˈn(y)ü-klē-ər How to pronounce nuclear (audio)
: of, relating to, or constituting a nucleus
: 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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