/ Dictionary / Index R real number: Meaning and Definition of Find definitions for: re'al num'ber Pronunciation: (rē'ul, rēl), [key] — Math. Math. a rational number or the limit of a sequence of rational numbers, as opposed to a complex number. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. realm real part Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language