Sens 2 : the action of spreading abroad or dispersing to or over every part of a
space or area; the condition or mode of being so dispersed or located all over an area;
sometimes without implying actual dispersal from a centre.[Source : OED]
Sens 3 : the orderly dividing of a mass or collective body into parts with
distinctive characters or functions; the orderly arrangement of the parts into which any whole
is divided; division and arrangement; classification.[Source : OED]