/ Dictionary / Index M monensin: Meaning and Definition of Find definitions for: mo•nen•sin Pronunciation: (mō-nen'sin), [key] — n. Biochem. a complex derivative of butyric acid, CHO, produced by the bacterium Streptomyces cinnamonensis and used as an antibiotic in animals. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Monel metal Monera Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language