Deny broadcast is contributing to uproar (6)
I believe the answer is:
disown
'deny' is the definition.
(to disown is to deny or reject)
'broadcast is contributing to uproar' is the wordplay.
'broadcast' becomes 'sow' (sowing is a kind of broadcasting).
'is contributing to' means one lot of letters goes inside another (inserted letters make a new contribution).
'uproar' becomes 'din' (both can mean a commotion or fuss).
'sow' placed within 'din' is 'DISOWN'.
(Other definitions for disown that I've seen before include "Repudiate or refuse to acknowledge a relationship" , "Refuse to be associated with (something/someone)" , "Repudiate - disinherit" , "Repudiate, disclaim" , "Refuse responsibility for" .)