/ Dictionary / Index M MB: Meaning and Definition of Find definitions for: MB Pronunciation: [key] Manitoba, Canada (approved for postal use). megabyte; megabytes. Mb Pronunciation: [key] megabit; megabits. mb Pronunciation: [key] millibar; millibars. millibarn; millibarns. M.B. Pronunciation: [key] Bachelor of Medicine. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mb (Thesaurus) Mazzini M'Ba Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language