Turkish port is unadulterated, they say (5)
I believe the answer is:
izmir
'turkish port' is the definition.
(I've seen this in another clue)
I don't understand the remainder of the clue.
(Other definitions for izmir that I've seen before include "Modern Smyrna" , "Turkish port, formerly Smyrna" , "Turkish city" , "Seaport and naval base in western Turkey" , "Turkish seaport, formerly called Smyrna" .)