Sack race reorganised to protect stunted bone (7)
I believe the answer is:
cashier
'sack' is the definition.
(I've seen this before)
'race reorganised to protect stunted bone' is the wordplay.
'reorganised' is an anagram indicator.
'to protect' indicates putting letters inside (inserted letters are protected or taken in).
'stunted bone' becomes 'shi' (I can't justify this - if you can you should give a lot more credence to this answer).
'race' is an anagram of 'caer'.
'caer' enclosing 'shi' is 'CASHIER'.
Can you help me to learn more?
(Other definitions for cashier that I've seen before include "banking officer" , "Employee who takes in or gives out money" , "Person dealing with money" , "employee accepting money" , "One handles the money" .)