Revoke, annul (6)
I believe the answer is:
cancel
I believe this is a double definition.
'revoke' is the first definition.
(I know that revoke is a more specific form of the action cancel)
'annul' is the second definition.
(I know that annul is a more specific form of the action cancel)
(Other definitions for cancel that I've seen before include "Annul or call off" , "Cross out or annul" , "Cross out or abolish" , "Go for an annulment" , "Discontinue" .)