Recess in a room or wall (6)
I believe the answer is:
alcove
'recess in a room or wall' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for alcove that I've seen before include "Niche - retreat" , "Small opening - a clove (anag)" , "Small recess in a larger room" , "Small opening off a larger room" , "compartment" .)