Snub polish again (6)
I believe the answer is:
rebuff
I believe this clue is a double definition.
'snub' is the first definition.
(I know that snub can be written as rebuff)
'polish again' is the second definition.
('buff' is an answer for 'polish' so perhaps 'rebuff' is OK for 'polish again')
(Other definitions for rebuff that I've seen before include "Reject abruptly" , "Reject bluntly" , "Turn off" , "Spurn, snub" , "Refuse" .)