Boggy terrain (9)
I believe the answer is:
marshland
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">boggy terrain</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 marshland that I've seen before include "damp patch" , "Boggy terrain" , "Waterlogged area" , "Boggy area" , "Boggy territory" .)