/ Dictionary / Index B Brownian movement: Meaning and Definition of Find definitions for: Brown'i•an move'ment Pronunciation: (brou'nē-un), [key] — Physics. Physics. the irregular motion of small particles suspended in a liquid or a gas, caused by the bombardment of the particles by molecules of the medium: first observed by Robert Brown in 1827. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. brown hyena brownie Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language