Room in church for vessels and vestments (6)
I believe the answer is:
vestry
'room in church for vessels and vestments' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for vestry that I've seen before include "Church changing room" , "vicar's office" , "Church room where clergy dress themselves" , "Room in a church where sacred vessels and vestments are kept" , "Storage and dressing room in a church" .)