Gaol (6)
I believe the answer is:
prison
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">gaol</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 prison that I've seen before include "porridge" , "Place of confinement" , "Place of detention for criminals" , "cage" , "Clink - jug" .)