Cancel, abolish (6)
I believe the answer is:
repeal
I believe this is a double definition.
'cancel' is the first definition.
(I know that repeal is a kind of cancel)
'abolish' is the second definition.
(thesaurus)
(Other definitions for repeal that I've seen before include "This is what O'Connell wanted" , "Annul, rescind" , "reversal of act" , "Abrogate" , "Rescind or withdraw a law" .)