Ending that's wrong in piece of footwear (7)
I believe the answer is:
closing
'ending' is the definition.
(I know that closing is a type of ending)
'wrong in piece of footwear' is the wordplay.
'wrong' becomes 'sin' (wrong can mean a sin or crime).
'in' indicates putting letters inside.
'piece of footwear' becomes 'clog' (I can't explain this - if you can you should believe this answer much more).
'sin' put within 'clog' is 'CLOSING'.
'that's' is the link.
Can you help me to learn more?
(Other definitions for closing that I've seen before include "Finishing" , "packing up" , "Shutting" , "Ending" .)