Passage one's going to broadcast (5)
I believe the answer is:
aisle
'passage' is the definition.
(aisle can mean a path or passageway)
'one's going to broadcast' is the wordplay.
'one' becomes 'i' (Roman numeral).
'going to' becomes 'll' (as in he'll, we'll etc).
'broadcast' shows a homophone (sound like) (how the word might sound on the radio or TV).
'i'+'ll'='ill'
'ill' sounds like 'AISLE'.
(Other definitions for aisle that I've seen before include "'Passage, gangway (5)'" , "Passageway between pews" , "Divide in a church" , "Here comes the bride" , "Part of a church" .)