Primitive scourge is polished (6)
I believe the answer is:
urbane
'is polished' is the definition.
(synonyms)
'primitive scourge' is the wordplay.
'primitive' becomes 'ur'.
'scourge' becomes 'bane' (synonyms).
'ur'+'bane'='URBANE'
(Other definitions for urbane that I've seen before include "Sophisticated and elegant - sounds citified" , "Unbare, being suave." , "Suave and sophisticated" , "Cosmopolitan" , "Polished -- sophisticated" .)