Room attached to a church (6)
I believe the answer is:
vestry
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">room attached to a church</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 vestry that I've seen before include "Somewhere in church" , "Part of church used as an office" , "Church sacristy" , "Office room in church" , "Church robing-room" .)