Main Entry: dif·fu·sion

Pronunciation: \dif-ˈyü-zhən\

Function: noun

1 : the process whereby particles of liquids, gases, or solids intermingle as the result of their spontaneous movement caused by thermal agitation and in dissolved substances move from a region of higher to one of lower concentration
2 a : reflection of light by a rough reflecting surface b : transmission of light through a translucent material

—dif·fu·sion·al \-ˈyüzh-nəl, -ən-^əl\ adjective