Definition of Brownian motion in English:

Brownian motion


  • [mass noun] The erratic random movement of microscopic particles in a fluid, as a result of continuous bombardment from molecules of the surrounding medium.

    • ‘The voltage signal produced by the photodiode is calibrated in force units using the power spectrum of Brownian motion.’
    • ‘Filaments of the cytoskeleton are so thin they can be pushed around by the random movements, or so-called Brownian motion, of other, neighboring molecules.’
    • ‘Second, he explained the jittery dance of microscopic particles - Brownian motion - as the buffets of surrounding atoms.’
    • ‘This does not occur in practice, since random forces such as Brownian motion perturb the cell's trajectory.’
    • ‘The amplitude of the displacements of unattached beads diminishes with a constant slope of - 2, as expected for Brownian motion in a viscous medium (sugar water).’


Late 19th century: named after Robert Brown (1773–1858), the Scottish botanist who first observed the motion.


Brownian motion

/ˌbraʊnɪən ˈməʊʃ(ə)n/