Chambers hosting American country (7)
I believe the answer is:
austria
'country' is the definition.
(Austria is an example)
'chambers hosting american' is the wordplay.
'chambers' becomes 'atria' (atrium is a kind of chamber).
'hosting' indicates putting letters inside.
'american' becomes 'us' (abbreviation for United States).
'atria' enclosing 'us' is 'AUSTRIA'.
(Other definitions for austria that I've seen before include "land in Europe" , "Original setting for Mozart" , "Central European country" , "Its ruling house was the Hapsburgs" , "The capital is Vienna (7)" .)