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

The experts from the Energy Department’s Idaho National Laboratory were sent to San Antonio to retrieve the plutonium and cesium on March 21, 2017, according to a Monday report from The Center for Public Integrity. Ryan Gaydos, Fox News, "Nuclear materials were reportedly stolen in Texas last year -- and they still haven't been found," 16 July 2018 Any amount of plutonium is also highly carcinogenic. Dan Goodin, Ars Technica, "Dangerous plutonium stolen from rental car in a hotel parking lot," 16 July 2018 And once the Agreed Framework collapsed, North Korea took the secured plutonium under its control and built about half a dozen additional nuclear weapons, testing its first in 2006. chicagotribune.com, "John Bolton is a national security threat," 23 Mar. 2018 Clinton reached an aid-for-disarmament deal in 1994 that halted North Korea's plutonium production for eight years, freezing what was then a very small atomic arsenal. Fox News, "AP FACT CHECK: Trump bobbles facts on NKorea history, nukes," 13 June 2018 Clinton reached an aid-for-disarmament deal in 1994 that halted North Korea’s plutonium production for eight years, freezing what was then a very small atomic arsenal. Washington Post, "AP FACT CHECK: Trump bobbles facts on NKorea history, nukes," 13 June 2018 South Carolina newspaper The State reported last week that the National Nuclear Security Administration has proposed modifying the MOX site to build plutonium pits, which would produce cores for nuclear weapons. Megan Geuss, Ars Technica, "Plan to make fuel from weapons-grade plutonium oxides dead on arrival," 13 May 2018 The Hanford site near Richland was used to make plutonium for atomic weapons. Hal Bernton, The Seattle Times, "Justice Department sues Washington state over law to compensate sick Hanford workers," 11 Dec. 2018 But our guys don’t get rid of the opposition by sticking plutonium in their teacups. Joe Queenan, WSJ, "We Can All Be Thankful America Doesn’t Have Putin," 24 Nov. 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

21 Jan 2019

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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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More from Merriam-Webster on plutonium

Rhyming Dictionary: Words that rhyme with plutonium

Spanish Central: Translation of plutonium

Nglish: Translation of plutonium for Spanish Speakers

Britannica.com: Encyclopedia article about plutonium

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