Country retreat, note (7)
I believe the answer is:
denmark
'country' is the definition.
(Denmark is an example)
'retreat note' is the wordplay.
'retreat' becomes 'den'.
'note' becomes 'mark' ('mark' can be a synonym of 'note').
'den'+'mark'='DENMARK'
(Other definitions for denmark that I've seen before include "Mark end of the country" , "Scandinavian country" , "Hamlet, Prince of . . . . . . . (7)" , "A country of dark men?" , "Aarhus is its second-largest city" .)