European sea (6)
I believe the answer is:
baltic
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">european sea</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for baltic that I've seen before include "Nearly land-locked sea of Scandinavia" , "Cab lit up the sea" , "Almost land-locked sea of Scandinavia" , "Sea in N.Europe" , "cold waters" .)