/ Dictionary / Index C circumradius: Meaning and Definition of Find definitions for: cir•cum•ra•di•us Pronunciation: (sûr"kum-rā'dē-us), [key] — pl. -di•i -di•us•es. the radius of the circle circumscribed around a triangle. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. circumpolar circumrotate Related Content Daily Word Quiz: lyceum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language