/ Dictionary / Index R reflectance: Meaning and Definition of Find definitions for: re•flect•ance Pronunciation: (ri-flek'tuns), [key] — n. Physics, Optics. the ratio of the intensity of reflected radiation to that of the radiation incident on a surface. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: reflectance (Thesaurus) reflect reflected plan Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language