Shed, with "off" (6)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">shed with off</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 slough that I've seen before include "Swamp; shed (dead skin)" , "shed covering" , "Swamp; Berkshire town" , "Berkshire town - bog - shed" , "poet wanted destroyed" .)