diffusion

Definition/Scope: The scattering of incident light by reflection from a rough surface; (2) the transmission of light through a translucent material; (3) the spontaneous intermingling of the particles of two or more substances as a result of random thermal motion.

Broader Terms:

physics

Narrower Terms:

atmospheric diffusion
colloids
dialysis
gaseous diffusion separation
osmosis
thermal diffusion
turbulent diffusion (meteorology)