diffusion

(noun) (physics) the process in which there is movement of a substance from an area of high concentration of that substance to an area of lower concentration.

(noun) the spread of social institutions (and myths and skills) from one society to another.

(noun) the property of being diffused or dispersed. Synonyms: dissemination.

(noun) the act of dispersing or diffusing something. Synonyms: dispersion, dispersal, dissemination. Examples: "The dispersion of the troops." "The diffusion of knowledge."