/ Dictionary / Index U unit circle: Meaning and Definition of Find definitions for: u'nit cir"cle Pronunciation: [key] — Math. Math. a circle whose radius has a length of one unit. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. unit character unit cost Related Content Daily Word Quiz: digression Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language