Great message about drone is broadcast (12)
I believe the answer is:
considerable
'great' is the definition.
(I've seen this before)
'message about drone is broadcast' is the wordplay.
'message' becomes 'cable' (cable is a kind of message).
'about' indicates putting letters inside.
'broadcast' indicates anagramming the letters (letters scattered or cast around).
'drone'+'is'='droneis'
'droneis' with letters rearranged gives 'onsider'.
'cable' going around 'onsider' is 'CONSIDERABLE'.
(Other definitions for considerable that I've seen before include "Notably large" , "Major" , "Great" , "Tidy" , "A lot (of) - worthy of respect" .)