Brownian movement: Meaning and Definition of

Brown'i•an move'ment

Pronunciation: (brou'nē-un), [key]
— Physics. Physics.
  1. 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.