noun, often attributive
ra·di·um | \ˈrā-dē-əm \

Definition of radium 

: an intensely radioactive brilliant white metallic element that resembles barium chemically, occurs in combination in minute quantities in minerals (such as pitchblende or carnotite), emits alpha particles and gamma rays to form radon, and is used chiefly in luminous materials and in the treatment of cancer — see Chemical Elements Table

Examples of radium in a Sentence

Recent Examples on the Web

Ash storage sites at the plant are leaking into surface water and groundwater upstream of drinking water intakes for more than 1 million people in the Charlotte region, the report says, calling the thallium and radium results alarming. Deon Roberts, charlotteobserver, "Groundwater at Duke Energy coal ash sites faulted for high radioactivity levels | Charlotte Observer," 20 Mar. 2018 In addition to beryllium, the soil contains lead and radioactive elements of thorium, radium and uranium. Keith Matheny, Detroit Free Press, "Radioactive soil from Ohio heads to Wayne County landfill next week," 22 June 2018 Back in Brandon, the city decisions on treating that radium are likely to take a year or more. CBS News, "Treating contaminated household water costly for cities – and consumers," 26 Jan. 2018 Treating Lacks’s cancer with crude radium implants—standard operating procedure in 1951—doctors were unable to save her life. Ryan P. Smith, Smithsonian, "Famed for “Immortal” Cells, Henrietta Lacks is Immortalized in Portraiture," 15 May 2018 Other tribes are also affected by the annual disposal of 100 million tons of coal ash, which is contaminated with arsenic, mercury, lead and radium. Evan Halper, latimes.com, "The Trump agenda has Native American tribes feeling under siege," 15 May 2018 The reports contained a few surprises, including high levels of radium and arsenic in some of the test wells, said Lisa Evans, senior counsel with Earthjustice, a nonprofit environmental law group. Sarah Bowman, Indianapolis Star, "New reports: Contaminants from coal ash at levels 40 times above safe drinking water standards," 28 Mar. 2018 At the time, radium was considered a miracle medicine, believed to extend life. Sherri Becker, Philly.com, "Medical mystery: Dental pain that grew agonizing, then deadly," 5 Mar. 2018 Vengosh added that the discovery at some sites of radium at levels far exceeding drinking water standards -- which can increase the risk of cancer -- were of particular concern. CBS News, "U.S. utilities find water pollution at coal-burning power plants," 2 Mar. 2018

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

1899, in the meaning defined above

History and Etymology for radium

New Latin, from Latin radius ray

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Statistics for radium

Last Updated

19 Sep 2018

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Time Traveler for radium

The first known use of radium was in 1899

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More Definitions for radium



English Language Learners Definition of radium

: a radioactive element that is used medically in cancer treatments


ra·di·um | \ˈrā-dē-əm \

Kids Definition of radium

: a strongly radioactive element found in very small quantities in various minerals (as pitchblende) and used in the treatment of cancer


noun, often attributive
ra·di·um | \ˈrād-ē-əm \

Medical Definition of radium 

: an intensely radioactive shining white metallic element that resembles barium chemically, that occurs in combination in minute quantities in minerals (as pitchblende or carnotite) principally as the isotope of mass number 226 formed from uranium 238, having a half-life of 1620 years, and emitting alpha particles and gamma rays to form radon, and that is used chiefly in luminous materials and in the treatment of cancer symbol Ra — see Chemical Elements Table

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Comments on radium

What made you want to look up radium? Please tell us where you read or heard it (including the quote, if possible).


exaggeratedly or childishly emotional

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