Breadcrumb Home > Dictionary > Index R refractometer: Meaning and Definition of Find definitions for: re•frac•tom•e•ter Pronunciation: (rē"frak-tom'i-tur), [key] — n. Optics. an instrument for determining the refractive index of a substance. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: refractometer (Thesaurus) refractivity refractor TrendingHere are the facts and trivia that people are buzzing about. Biographies: Notable Jewish Religious Leaders Current Events This Week: September 2023 Hispanic Population and the 2010 U.S. Census Preamble of the United Nations Charter The Jewish Calendar ✖ Related Content Daily Word Quiz: radula Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language