Irish channel securing opera about to broadcast (7)
I believe the answer is:
radiate
'broadcast' is the definition.
(I've seen this before)
'irish channel securing opera about' is the wordplay.
'irish channel' becomes 'rte' (Irish state broadcaster Raidio Teilifis Eireann).
'securing' means one lot of letters goes inside another.
'opera' becomes 'aida' (Aida is an example).
'about' is a reversal indicator.
'aida' backwards is 'adia'.
'rte' going around 'adia' is 'RADIATE'.
'to' is the link.
(Other definitions for radiate that I've seen before include "Give out (light, etc)" , "broadcast" , "Travel from centre in all directions" , "Disseminate" , "Spread outwards" .)