/ Dictionary / Index M M-series: Meaning and Definition of Find definitions for: M-se•ries Pronunciation: (em'sēr"ēz), [key] — n. Physics. See under Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. M.S.Ent. M.S.F. Related Content Daily Word Quiz: belligerent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language