/ Dictionary / Index M millesimal: Meaning and Definition of Find definitions for: mil•les•i•mal Pronunciation: (mi-les'u-mul), [key] — adj. thousandth. —n. a thousandth part. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Milles millet Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language