Chap returned hymnbook in sack (9)
I believe the answer is:
dismissal
'sack' is the definition.
(I know that sack can be written as dismissal)
'chap returned hymnbook' is the wordplay.
'chap' becomes 'sid' (man's name).
'returned' shows that the letters should be reversed in order.
'hymnbook' becomes 'missal' (I can't explain this - if you can you should give a lot more credence to this answer).
'sid' backwards is 'dis'.
'dis'+'missal'='DISMISSAL'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for dismissal that I've seen before include "Discharge" , "Release - marching orders!" , "Rejection" , "removal from office" , "ending" .)