Organ case, adapted rice bag (7)
I believe the answer is:
ribcage
'organ case' is the definition.
(I've seen this before)
'adapted rice bag' is the wordplay.
'adapted' indicates anagramming the letters.
'rice'+'bag'='ricebag'
'ricebag' is an anagram of 'RIBCAGE'.
(Other definitions for ribcage that I've seen before include "part of chest" , "Bones attached to the sternum" , "bony frame" , "(Bones in) chest wall" , "Bone structure of chest wall" .)