Behind bars, imprisoned (6)
I believe the answer is:
inside
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">behind bars</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(inside can mean in prison)</span><br/ ><br/ >'<span class="explanation-format__original">imprisoned</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ ></span>
(Other definitions for inside that I've seen before include "Middle" , "Stomach etc - in prison?" , "Not external, perhaps in prison" , "Jailed" , "locked up" .)