radium

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

|Updated on: 30 May 2018

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

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Recent Examples of radium from the Web

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
At Marshall, on the northern banks of Lake Norman in Catawba County, radioactivity levels from radium were 2.5 times that federal drinking water standard, the report says.

— deon roberts, charlotteobserver, "Groundwater at Duke Energy coal ash sites faulted for high radioactivity levels | Charlotte Observer," 20 Mar. 2018
The highest levels of radioactivity were found at Duke’s Asheville plant, where radium in groundwater was 38 times what the Environmental Protection Agency considers safe for drinking water, according to the report.

— deon roberts, charlotteobserver, "Groundwater at Duke Energy coal ash sites faulted for high radioactivity levels | Charlotte Observer," 20 Mar. 2018
At more than 70 sites across the country, toxins like arsenic, mercury, and radium are leaching into groundwater from pond-like storage pits filled with the sludgy leftovers of coal burning.

— emily atkin, The New Republic, "Is Coal Waste Leaching Into America’s Drinking Water?," 12 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.

Origin and Etymology of radium

New Latin, from Latin radius ray

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First Known Use: 1899

in the meaning defined above

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RADIUM Defined for English Language Learners

radium

noun

Definition of radium for English Language Learners

: a radioactive element that is used medically in cancer treatments

RADIUM Defined for Kids

radium

noun ra·di·um \ ˈrā-dē-əm \

Definition of radium for Students

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

Medical Dictionary

radium

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