Harry pours me big shot (7)
I believe the answer is:
supremo
'big shot' is the definition.
(both can mean an important person)
'harry pours me' is the wordplay.
'harry' indicates anagramming the letters (harry can mean to attack or spoil).
'pours'+'me'='poursme'
'poursme' is an anagram of 'SUPREMO'.
(Other definitions for supremo that I've seen before include "Big cheese, head honcho" , "Person in overall authority" , "Overall head" , "Leader with unlimited powers" , "Person invested with great authority" .)