Revolting person's endless unmerited broadcast (8)
I believe the answer is:
mutineer
'revolting person's' is the definition.
(someone revolting against authority)
'endless unmerited broadcast' is the wordplay.
'endless' means to remove the last letter.
'broadcast' is an anagram indicator (letters scattered or cast around).
'unmerited' with its last letter removed is 'unmerite'.
'unmerite' with letters rearranged gives 'MUTINEER'.
(Other definitions for mutineer that I've seen before include "Rebellious soldier" , "Military rebel" , "Maybe Christian" , "Seditionist" , "An army rebel" .)