Charm ebbed unexpectedly in sleeping quarters (10)
I believe the answer is:
bedchamber
'sleeping quarters' is the definition.
(a bedroom)
'charm ebbed unexpectedly' is the wordplay.
'unexpectedly' indicates anagramming the letters.
'charm'+'ebbed'='charmebbed'
'charmebbed' is an anagram of 'BEDCHAMBER'.
'in' is the link.
(Other definitions for bedchamber that I've seen before include "Room for sleeping" , "Where there may be a four-poster" , "place for retirement" .)