Nouns

(n)diffusion(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
(n)diffusionthe spread of social institutions (and myths and skills) from one society to another
(n)dissemination, diffusionthe property of being diffused or dispersed
(n)dispersion, dispersal, dissemination, diffusionthe act of dispersing or diffusing something“the dispersion of the troops”, “the diffusion of knowledge”