/ Dictionary / Index R radiant emittance: Meaning and Definition of Find definitions for: ra'diant emit'tance Pronunciation: (ik-sīt'ns). [key] — Optics. Optics. radiant flux emitted per unit area. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. radiant radiant energy Related Content Daily Word Quiz: portent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language