Approval when broadcast (6)
I believe the answer is:
assent
'approval' is the definition.
(thesaurus)
'when broadcast' is the wordplay.
'when' becomes 'as'.
'broadcast' becomes 'sent' (I've seen this in other clues).
'as'+'sent'='ASSENT'
(Other definitions for assent that I've seen before include "Agree - concede" , "Agree, acquiesce" , "Okay" , "Permission" , "Official sanction" .)