Pious type to assess extremely greedy policy (8)
I believe the answer is:
strategy
'policy' is the definition.
(thesaurus)
'pious type to assess extremely greedy' is the wordplay.
'pious type' becomes 'st' (saint).
'to assess' becomes 'rate' (rating is a kind of assessing).
'extremely' says to hollow out the word (remove centre letters).
'greedy' with its middle removed is 'gy'.
'st'+'rate'+'gy'='STRATEGY'
(Other definitions for strategy that I've seen before include "Plan of action, tactics" , "Art of military planning" , "Overall plan for campaign" , "Scheme" , "Approach" .)