Breadcrumb Home > Dictionary > Index O optical rotation: Meaning and Definition of Find definitions for: op'tical rota'tion Pronunciation: [key] — Physical Chem. Physical Chem. the angle at which the plane of polarized light is rotated when passed through an optically active substance. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. optical pumping optical scanning TrendingHere are the facts and trivia that people are buzzing about. Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 12 Steps to a New Year New Year's Resolution to Slim Down? Martin Luther King Speeches Books of the Bible: Old Testament Books in Order ✖ Related Content Daily Word Quiz: minatory Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language