/ Dictionary / Index C circular dichroism: Meaning and Definition of Find definitions for: cir'cular di'chroism Pronunciation: [key] — Optics. Optics. selective absorption of one of the two possible circular polarizations of light. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. circular definition circular error Related Content Daily Word Quiz: diligent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language