Communal dining hall (9)
I believe the answer is:
refectory
'communal dining hall' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for refectory that I've seen before include "dining area" , "Monastic dining hall" , "Communal dining room" , "Communal room for meals" , "Communal dining hall" .)