an intensely radioactive metallic element that occurs in minute amounts in uranium ores
The chemical element (symbol Ra) with an atomic number of 88. It is a soft, shiny and silvery radioactive alkaline earth metal.
To treat (a tumour, etc.) with radium.
The name radium comes from the French word radium, which combines radioactif meaning "radioactive" with the suffix -ium used for metallic elements. It was coined to describe this newly discovered radioactive metal.