Swiss lake (6)
I believe the answer is:
geneva
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">swiss lake</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for geneva that I've seen before include "Avenge in Swiss city" , "Average in Swiss city" , "old Calvinist stronghold" , "International agreement on the treatment of civilians and captured or wounded military personnel in wartime" , "European city" .)