Stop back (6)
I believe the answer is:
hinder
This clue is a double definition.
'stop' is the first definition.
(thesaurus)
'back' is the second definition.
(I've seen this before)
(Other definitions for hinder that I've seen before include "stop" , "Obstruct or hold back" , "Keep back by delaying progress" , "Impede, keep back" , "Bow user" .)