Polish official in East (6)
I believe the answer is:
refine
'polish' is the definition.
('refine' can be a synonym of 'polish')
'official in east' is the wordplay.
'official' becomes 'ref' (match official in football, say).
'east' becomes 'e' ('E' can be a synonym of 'east').
'ref'+'in'+'e'='REFINE'
(Other definitions for refine that I've seen before include "Remove impurities or make cultured" , "Cleanse from impurities" , "Make pure" , "Purify or improve" , "Get rid of impurities" .)