/ Dictionary / Index M millibarn: Meaning and Definition of Find definitions for: mil•li•barn Pronunciation: (mil'u-bärn"), [key] — n. one thousandth of a barn. Abbr.: mb Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. millibar Millicent Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language