Uproar of billions over murdered brother (5)
I believe the answer is:
babel
'uproar' is the definition.
(thesaurus)
'billions over murdered brother' is the wordplay.
'billions' becomes 'b'.
'over' is a charade indicator (letters next to each other).
'murdered brother' becomes 'abel'.
'b'+'abel'='BABEL'
'of' acts as a link.
(Other definitions for babel that I've seen before include "incoherent sounds" , "Commotion" , "racket" , "Biblical city with a tower" , "Vocal confusion" .)