Poles overwhelmed by divine being's stupidness (7)
I believe the answer is:
density
'stupidness' is the definition.
'poles overwhelmed by divine being's' is the wordplay.
'poles' becomes 'ns' (North and South poles).
'overwhelmed by' indicates putting letters inside (I've seen this in other clues).
'divine being' becomes 'deity'.
'ns' inserted into 'deity' is 'DENSITY'.
(Other definitions for density that I've seen before include "showing obtuseness" , "The quantity of a given area" , "there's stupidity for you!" , "Degree of compactness" , "It's usually measured in grammes per cc" .)