/ Dictionary / Index R radium therapy: Meaning and Definition of Find definitions for: ra'dium ther"apy Pronunciation: [key] treatment of disease by means of radium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. radium sulfate radius Related Content Daily Word Quiz: dissonant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language