/ Dictionary / Index M mo: Meaning and Definition of Find definitions for: mo Pronunciation: (mō), [key] — n. Informal. moment (def. 1). -mo Pronunciation: [key] a suffix occurring in a series of compounds that describe book sizes according to the number of leaves formed by the folding of a single sheet of paper: sixteenmo. MO Pronunciation: [key] method of operation. Missouri (approved esp. for use with zip code). mode of operation. modus operandi. Mo Pronunciation: [key] molybdenum. Mo. Pronunciation: [key] Missouri. Monday. mo. Pronunciation: [key] — pl. mos. month. months. M.O. Pronunciation: [key] mail order. manually operated. Medical Officer. method of operation. mode of operation. modus operandi. money order. m.o. Pronunciation: [key] mail order. modus operandi. money order. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mo (Thesaurus) M.Nurs. moa Related Content Daily Word Quiz: abominable Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language