Killer repositioned headless Schubert
I believe the answer is:
butcher
'killer' is the definition.
(butcher is a kind of killer)
'repositioned headless schubert' is the wordplay.
'repositioned' indicates anagramming the letters.
'headless' means to remove the first letter.
'schubert' with its initial letter taken off is 'chubert'.
'chubert' anagrammed gives 'BUTCHER'.
(Other definitions for butcher that I've seen before include "One sells meat" , "Meat seller" , "Meat purveyor" , "In EastEnders, Pat maybe" , "Kill - food retailer" .)