Refuse to acknowledge row about broadcast (6)
I believe the answer is:
disown
'refuse to acknowledge' is the definition.
(I've seen this before)
'row about broadcast' is the wordplay.
'row' becomes 'din' (both can mean a loud disturbance).
'about' means one lot of letters goes inside another.
'broadcast' becomes 'sow' (sowing is a kind of broadcasting).
'din' placed around 'sow' is 'DISOWN'.
(Other definitions for disown that I've seen before include "Refuse to have anything to do with" , "Deny any connection with" , "Refuse to be associated with (a person)" , "Disclaim all connection or relationship with" , "Repudiate, disclaim" .)