ra·​don | \ ˈrā-ˌdän How to pronounce radon (audio) \

Definition of radon

: a heavy radioactive gaseous element formed by the decay of radium — see Chemical Elements Table

Examples of radon in a Sentence

Recent Examples on the Web Thawing Arctic permafrost will expose local populations to more radon, and the iodine of desert dust may decrease ozone pollution but increase greenhouse gas longevity. Rafil Kroll-zaidi, Harper’s Magazine , 25 May 2022 The report also recommended that all results of radon tests conducted on Utah structures be reported to DEQ and put on an online database. Brian Maffly, The Salt Lake Tribune, 20 May 2022 The radiological team charged with looking for both radiation and radon has concluded. Caitlin O'kane, CBS News, 25 Apr. 2022 The Marion County Public Health Department offers free radon testing for county residents. Sarah Bowman, The Indianapolis Star, 17 Nov. 2021 The spring water in Tskaltubo is said to have a high level of radon, which has long been believed to decrease inflammation. Jamie Ditaranto, Condé Nast Traveler, 28 Sep. 2021 The average level of indoor radon in the U.S. is 1.3 picocuries per liter. Austen Erblat, sun-sentinel.com, 2 Sep. 2021 With federal assistance, Florida has acted on the recommendations of dozens of local health departments to investigate environmental pollution, like groundwater contamination or radon levels in the air. Lulu Ramadan, ProPublica, 22 Aug. 2021 Basically, the fan sucks the radon from underneath the basement floor and discharges it into the outside atmosphere. ... Steve Metsch, chicagotribune.com, 4 June 2021 See More

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

First Known Use of radon

1918, in the meaning defined above

History and Etymology for radon

International Scientific Vocabulary, from radium

Learn More About radon

Dictionary Entries Near radon



radon seed

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Statistics for radon

Last Updated

26 May 2022

Cite this Entry

“Radon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radon. Accessed 27 May. 2022.

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More Definitions for radon


ra·​don | \ ˈrā-dän How to pronounce radon (audio) \

Medical Definition of radon

: a heavy radioactive gaseous element of the group of inert gases formed by disintegration of radium and used similarly to radium in medicine symbol Rn

called also radium emanation

— see Chemical Elements Table

More from Merriam-Webster on radon

Nglish: Translation of radon for Spanish Speakers

Britannica English: Translation of radon for Arabic Speakers

Britannica.com: Encyclopedia article about radon


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