Polish city on the Baltic (6)
I believe the answer is:
gdansk
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">polish city on the baltic</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for gdansk that I've seen before include "Polish Baltic port" , "Port city of Poland" , "Polish city on the Baltic" , "Polish coastal city" , "Major Polish port" .)