Hinder — prevent (4)
I believe the answer is:
foil
I believe this clue is a double definition.
'hinder' is the first definition.
(thesaurus)
'prevent' is the second definition.
(I know that foil is a more specific form of the action prevent)
(Other definitions for foil that I've seen before include "Scotch" , "Repulse" , "shiny paper" , "Check" , "Thwart - contrasting thing - sword" .)