Icy hazard at sea (4)
I believe the answer is:
berg
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">icy hazard at sea</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for berg that I've seen before include "Mountain (in German, South African)" , "trouble at sea" , "African mount" , "Large mass of floating ice" , "feature of icy waters" .)