fissile

adjective
fis·​sile | \ ˈfi-səl How to pronounce fissile (audio) , ˈfi-ˌsī(-ə)l \

Definition of fissile

1 : capable of or prone to being split or divided in the direction of the grain or along natural planes of cleavage fissile wood fissile crystals
2 : capable of undergoing fission

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Other Words from fissile

fissility \ fi-​ˈsi-​lə-​tē How to pronounce fissility (audio) \ noun

Did You Know?

When scientists first used fissile back in the 1600s, the notion of splitting the nucleus of an atom would have seemed far-fetched indeed. In those days, people thought that atoms were the smallest particles of matter that existed and therefore could not be split. Fissile (which can be traced back to Latin findere, meaning "to split") was used in reference to things like rocks. When we hear about "fissile materials" today, the reference is usually to nuclear fission: the splitting of an atomic nucleus that releases a huge amount of energy. But there is still a place in our language for the original sense of fissile (and for the noun fissility, meaning "the quality of being fissile"). A geologist, for example, might refer to slate as being fissile.

Examples of fissile in a Sentence

Recent Examples on the Web Yet, Iran hawks argue that Biden should use the Trump-era sanctions to press for a deal that eliminates the regime’s capacity to enrich fissile material. Joel Gehrke, Washington Examiner, "Pompeo team urges Biden to use Trump sanctions as 'leverage' in expected Iran talks," 12 Nov. 2020 The aging facility about 60 miles north of Pyongyang was once the main source of its fissile material, turning out roughly enough plutonium each year for one atomic bomb. Washington Post, "Keeping Up With the Plot of the Trump-Kim Nuclear Show," 9 Oct. 2019 The aging facility about 60 miles north of Pyongyang was once the main source of its fissile material, turning out roughly enough plutonium each year for one atomic bomb. Washington Post, "Keeping Up With the Plot of the Trump-Kim Nuclear Show," 9 Oct. 2019 Centrifuges, which change the chemical properties of uranium to separate out the most fissile isotope – a material capable of sustaining a nuclear fission chain reaction called U-235. Tanya Edwards, refinery29.com, "What To Know About The Iran Nuclear Deal After Trump’s Address," 9 Jan. 2020 Where does Kim’s military get its fissile material? Jon Herskovitz | Bloomberg, Washington Post, "How Kim Jong Un Keeps Advancing North Korea’s Nuclear Program," 13 Dec. 2019 Under that deal, in exchange for the lifting of Western economic sanctions, Iran agreed that no fissile material — the makings of bomb fuel — would be put in the centrifuges spinning at the site. Michael Wolgelenter, New York Times, "Iran Steps Further From Nuclear Deal With Move on Centrifuges," 5 Nov. 2019 Bolton had said North Korea should hand over its nuclear weapons and fissile material to the United States the way Libya did in early 2004 in exchange for normalized relations and relief from sanctions. Victoria Kim, Los Angeles Times, "North Korea launches missile into waters near Japan days before nuclear talks set to resume with U.S.," 1 Oct. 2019 Under the agreement, Iran is allowed limited research and development on advanced centrifuges, which accelerate the production of fissile material that can be used to make a nuclear bomb. Erin Cunningham, Washington Post, "Iran now operating advanced centrifuges in breach of nuclear pact," 9 Sep. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'fissile.' 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 fissile

1661, in the meaning defined at sense 1

History and Etymology for fissile

borrowed from Latin fissilis "easily split," from fid-, variant stem of findere "to split, cleave" + -tilis "subject to, susceptible to (the action of the verb)" — more at bite entry 1

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The first known use of fissile was in 1661

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Last Updated

16 Nov 2020

Cite this Entry

“Fissile.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fissile. Accessed 4 Dec. 2020.

More from Merriam-Webster on fissile

Nglish: Translation of fissile for Spanish Speakers

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