/ Dictionary / Index Q quinoidine: Meaning and Definition of Find definitions for: qui•noi•dine Pronunciation: (kwi-noi'dēn, -din), [key] — n. Pharm. a brownish-black, resinous substance consisting of a mixture of alkaloids, obtained as a by-product in the manufacture of quinine and formerly used as a cheap substitute for it. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. quinoid quinol Related Content Daily Word Quiz: abstain Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language