DIFFUSENESS
diffuseness
(noun) the spatial property of being spread out over a wide area or through a large volume
Source: WordNet® 3.1
Etymology
Noun
diffuseness (usually uncountable, plural diffusenesses)
(uncountable) The state or quality of being diffuse.
(countable) The result or product of being diffuse.
Source: Wiktionary
Dif*fuse"ness, n.
Definition: The quality of being diffuse; especially, in writing, the use
of a great or excessive number of word to express the meaning;
copiousness; verbosity; prolixity.
Source: Webster’s Unabridged Dictionary 1913 Edition