Source : Webster's Revised Unabridged Dictionary (1913)

Dispersion \Dis*per"sion\, n. [CF. F. dispersion.]
   1. The act or process of scattering or dispersing, or the
      state of being scattered or separated; as, the Jews in
      their dispersion retained their rites and ceremonies; a
      great dispersion of the human family took place at the
      building of Babel.

            The days of your slaughter and of your dispersions
            are accomplished.                     --Jer. xxv.
                                                  34.

   2. (Opt.) The separation of light into its different colored
      rays, arising from their different refrangibilities.

   {Dispersion of the optic axes} (Crystallog.), the separation
      of the optic axes in biaxial crystals, due to the fact
      that the axial angle has different values for the
      different colors of the spectrum.

Source : WordNet®

dispersion
     n 1: spreading widely or driving off [syn: {scattering}]
     2: the spatial property of being scattered about over an area
        or volume [syn: {distribution}] [ant: {concentration}]
     3: the act of dispersing or diffusing something; "the
        dispersion of the troops"; "the diffusion of knowledge"
        [syn: {dispersal}, {dissemination}, {diffusion}]