Criticise American urban greed (8)
I believe the answer is:
rapacity
'greed' is the definition.
(I know that greed can be written as rapacity)
'criticise american urban' is the wordplay.
'criticise' becomes 'rap' (I've seen this before).
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'urban' becomes 'city'.
'rap'+'a'+'city'='RAPACITY'
(Other definitions for rapacity that I've seen before include "Great greed and exploitation of others" , "The plundering and robbing of others - sheer greediness" , "Predatory greed and extortion" , "Extreme greed and predatory quality" , "excessive greed" .)