/di sperr"zheuhn, -sheuhn/ , n.
1. Also, dispersal . an act, state, or instance of dispersing or of being dispersed.
2. Optics.
a. the variation of the index of refraction of a transparent substance, as glass, with the wavelength of light, with the index of refraction increasing as the wavelength decreases.
b. the separation of white or compound light into its respective colors, as in the formation of a spectrum by a prism.
3. Statistics. the scattering of values of a variable around the mean or median of a distribution.
4. Mil. a scattered pattern of hits of bombs dropped under identical conditions or of shots fired from the same gun with the same firing data.
5. Also called disperse system . Physical Chem. a system of dispersed particles suspended in a solid, liquid, or gas.
6. ( cap. ) Diaspora (def. 1).
[ 1350-1400; ME dispersio ( u ) n ( dispersion- (s. of dispersio ), equiv. to dispers ( us ) (see DISPERSE) + -ion- -ION ]