/ Dictionary / Index M MLB: Meaning and Definition of Find definitions for: MLB Pronunciation: [key] Maritime Labor Board. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. M.L.Arch. MLD Related Content Daily Word Quiz: clairvoyant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language