/ Dictionary / Index R radically: Meaning and Definition of Find definitions for: rad•i•cal•ly Pronunciation: (rad'ik-lē), [key] — adj. with regard to origin or root. in a complete or basic manner; thoroughly; fundamentally. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: radically (Thesaurus) radical left radical right Related Content Daily Word Quiz: modify Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language