plutonium

noun
plu·to·ni·um | \plü-ˈtō-nē-əm \

Definition of plutonium 

: a radioactive metallic element similar chemically to uranium that is formed as the isotope 239 by decay of neptunium and found in minute quantities in pitchblende, that undergoes slow disintegration with the emission of an alpha particle to form uranium 235, and that is fissionable with slow neutrons to yield atomic energy — see Chemical Elements Table

Examples of plutonium in a Sentence

Recent Examples on the Web

North Korea agreed to freeze a plutonium weapons program in exchange for energy and economic aid. David Jackson, USA TODAY, "Trump's goal of total 'denuclearization' of North Korea is a long shot," 7 June 2018 North Korea also has a supply of plutonium, highly enriched uranium and other supplies that the U.S. wants to know more about. Mahita Gajanan, Time, "Why President Trump's North Korea Summit Is Still Likely to Happen, According to a Top Expert," 24 May 2018 However, there were no documents saying the plutonium had been properly disposed. Fox News, "Idaho State University loses weapons-grade plutonium capable of making a dirty bomb," 8 May 2018 However, there were no documents saying the plutonium had been properly disposed. CBS News, "Idaho State University faces fine for losing plutonium used to make dirty bombs," 8 May 2018 The improvements to the Yongbyon facility include modifications to a plutonium production reactor’s cooling system and various support facilities. Kim Hjelmgaard, USA TODAY, "North Korea upgrades nuclear facility despite Trump-Kim summit, satellite images show," 28 June 2018 Even the recent revelations of seemingly modest North Korean progress on missile technology and the production of nuclear fuel — including continued work on a new nuclear reactor that can produce plutonium — have not dimmed Mr. Trump’s enthusiasm. David E. Sanger, New York Times, "How Trump Went From ‘Fire and Fury’ to Dismissing North Korean Nuclear Advances," 4 July 2018 The Energy Department wants to ramp up production to 80 plutonium cores a year by 2030. Susan Montoya Bryan, chicagotribune.com, "U.S. to decide best site option for nuclear weapons production," 9 May 2018 Their assignment is to retrieve three highly dangerous plutonium cores from a man code-named John Lark, who is working with anarchist terror-network The Syndicate (yes, them again) to bring down the free world. refinery29.com, "Mission Impossible: Fallout Is As Wild & Fun As Henry Cavill's Mustache," 12 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'plutonium.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of plutonium

1942, in the meaning defined above

History and Etymology for plutonium

New Latin, from Pluton-, Pluto, the planet Pluto

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Statistics for plutonium

Last Updated

14 Oct 2018

Look-up Popularity

Time Traveler for plutonium

The first known use of plutonium was in 1942

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More Definitions for plutonium

plutonium

noun

English Language Learners Definition of plutonium

: a radioactive element that is used to make nuclear energy and nuclear weapons

plutonium

noun
plu·to·ni·um | \plü-ˈtō-nē-əm \

Kids Definition of plutonium

: a radioactive metallic chemical element formed from neptunium and used for releasing atomic energy

plutonium

noun
plu·to·ni·um | \plü-ˈtō-nē-əm \

Medical Definition of plutonium 

: a radioactive metallic element similar chemically to uranium that is formed as the isotope 239 by decay of neptunium and found in minute quantities in pitchblende, that undergoes slow disintegration with the emission of an alpha particle to form uranium 235, and that is fissionable with slow neutrons to yield atomic energy symbol Pu — see Chemical Elements Table

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