ra·​don ˈrā-ˌdän How to pronounce radon (audio)
: 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. Alexander Sammon, Harper's Magazine, 25 June 2022 But the amount of radon in each home varies widely. Andy Larsen, The Salt Lake Tribune, 22 July 2023 Mitigation can reduce the level of radon by 99%, and the type of mitigation varies on the type of home. Dr. Keith Roach, oregonlive, 15 Mar. 2023 In addition, the builder’s homes have the necessary piping for radon abatement, if that should be necessary. Hartford Courant, 4 Feb. 2023 These include a family history of cancer and exposure to asbestos, radon and air pollution. Estelamari Rodriguez, Fortune, 1 Feb. 2023 January is awareness month for thyroids, glaucoma, birth defects, cervical health, radon and blood donations. Scott Lafee, San Diego Union-Tribune, 3 Jan. 2023 In contrast, houses built on piles are protected, as the radon escapes to the atmosphere. Chris Baraniuk- Knowable Magazine, Discover Magazine, 21 May 2022 Some preliminary research has found that environmental toxins such as nitrate and radon—which can turn up in drinking water—may also raise a person’s risk for kidney cancer. Markham Heid, Time, 13 Dec. 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'radon.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


International Scientific Vocabulary, from radium

First Known Use

1918, in the meaning defined above

Time Traveler
The first known use of radon was in 1918

Dictionary Entries Near radon

Cite this Entry

“Radon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radon. Accessed 10 Dec. 2023.

Kids Definition


ra·​don ˈrā-ˌdän How to pronounce radon (audio)
: a heavy radioactive gaseous element formed by the breaking apart of radium atoms see element

Medical Definition


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

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!