Repudiate, deny (7)
I believe the answer is:
disavow
I believe this is a double definition.
'repudiate' is the first definition.
(I've seen this in another clue)
'deny' is the second definition.
(I know that disavow is a more specific form of deny)
(Other definitions for disavow that I've seen before include "To deny knowledge of" , "To deny support" , "Deny responsibility for (something)" , "Refuse to acknowledge" , "Disclaim" .)