Refuse to acknowledge racket surrounding pig (6)
I believe the answer is:
disown
'refuse to acknowledge' is the definition.
(I've seen this before)
'racket surrounding pig' is the wordplay.
'racket' becomes 'din' (both can mean a loud noise or disturbance).
'surrounding' means one lot of letters goes inside another.
'pig' becomes 'sow' (I've seen this in another clue).
'din' enclosing 'sow' is 'DISOWN'.
(Other definitions for disown that I've seen before include "Forsake" , "Refuse to be associated with (a person)" , "Disclaim all connection or relationship with" , "Repudiate - disinherit" , "Reject all connection or relationship with" .)