Prison rooms (5)
I believe the answer is:
cells
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">prison rooms</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 cells that I've seen before include "terrorist groups" , "Rooms for prisoners" , "Dungeons" , "Accommodation for prisoners" , "Small rooms" .)