Chamber (4)
'chamber' is the definition.
(I know that chamber can be written as room)
This is the entire clue.
(Other definitions for room that I've seen before include "Scope; living space" , "Chamber; scope" , "See 17" , "Latitude" , "kitchen?" .)
(Other definitions for echo that I've seen before include "Languishing nymph" , "Reflect sound" , "Comms code word for E" , "A natural sound reflection" , "Greek girl in love with Narcissus" .)
'chamber' is the definition.
(I know that atrium is a type of chamber)
This is all the clue.
(Other definitions for atrium that I've seen before include "Central courtyard" , "An upper cavity in the heart" , "Central court of old Roman house, or heart cavity" , "Roman courtyard" , "High central hall in large building" .)