/ Dictionary / Index M monoester: Meaning and Definition of Find definitions for: mon•o•es•ter Pronunciation: (mon"ō-es'tur), [key] — n. Chem. a single esterified polybasic acid. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. monoecious monoestrous 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