Quantcast
Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Medical
  • Scrabble
  • Spanish Central
  • Learner's Dictionary

radium

play
noun ra·di·um \ˈrā-dē-əm\

Simple Definition of radium

  • : a radioactive element that is used medically in cancer treatments

Full Definition of radium

  1. :  an intensely radioactive brilliant white metallic element that resembles barium chemically, occurs in combination in minute quantities in minerals (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 element table

Origin of radium

New Latin, from Latin radius ray


First Known Use: 1899

Rhymes with radium


RADIUM Defined for Kids

radium

play
noun ra·di·um \ˈrā-dē-əm\

Definition of radium

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




Medical Dictionary

radium

play
noun ra·di·um \ˈrād-ē-əm\

Medical Definition of radium

  1. :  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 element table




Learn More about radium


Seen and Heard

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

WORD OF THE DAY

February 8, 2016

to clear from accusation or blame

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

image1037863653

Which of the following refers to thin, bending ice, or to the act of running over such ice?

spindrift duvet pince-nez kittly-benders
Name That Thing

10 quick questions: hear them, spell them, and see how your skills compare to the crowd.

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ