/ Dictionary / Index R radio knife: Meaning and Definition of Find definitions for: ra'dio knife" Pronunciation: [key] ? Surg. Surg. an electrical instrument for cutting tissue that by searing severed blood vessels seals them and prevents bleeding. Random House Unabridged Dictionary, Copyright 1997, by Random House, Inc., on Infoplease. radioisotope radiolabel Related Content Daily Word Quiz: abdicate Analogy of the Day: Today?s Analogy Spelling Bee: Today?s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language