Cell (7)
I believe the answer is:
dungeon
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">cell</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that Dungeon is a type of cell)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for dungeon that I've seen before include "part of prison" , "Uncongenial accommodation" , "Unpleasant cell" , "Keep" , "Place of confinement underground" .)