radium

noun, often attributive ra·di·um \ ˈrā-dē-əm \
Updated on: 8 Nov 2017

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

Recent Examples of radium from the Web

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


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


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of very fine texture or delicate form

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