/ Dictionary / Index M millibar: Meaning and Definition of Find definitions for: mil•li•bar Pronunciation: (mil'u-bär"), [key] — n. a centimeter-gram-second unit of pressure equal to one thousandth of a bar or 1000 dynes per square centimeter, used to measure air pressure. Abbr.: mb Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: millibar (Thesaurus) milliary millibarn 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