Opening style of moving broadcast (4)
I believe the answer is:
gate
'opening' is the definition.
(a gate is an opening or entrance)
'style of moving broadcast' is the wordplay.
'style of moving' becomes 'gait' (someone's way of moving).
'broadcast' shows a homophone (sound like) (how the word might sound on the radio or TV).
'gait' is a homophone of 'GATE'.
(Other definitions for gate that I've seen before include "Hinged barrier in an entrance" , "Five-bar opening?" , "Frame for closing an entrance" , "Facility in airport" , "Kind of door as in wall or fence" .)