Welshman heading off with group for broadcast (6)
I believe the answer is:
airing
'broadcast' is the definition.
(to air is to broadcast on TV)
'welshman heading off with group' is the wordplay.
'welshman' becomes 'dai' (Welsh name).
'heading off' means to remove the first letter.
'with' means one lot of letters go next to another.
'group' becomes 'ring' (a ring is a criminal organisation).
'dai' with its first letter taken off is 'ai'.
'ai'+'ring'='AIRING'
'for' is the link.
(Other definitions for airing that I've seen before include "Broadcast" , "Ventilating, say a grievance" , "Expressing (an opinion) publicly" , "Publicity" , "Ventilation" .)