Running over as rationing's broadcast (12)
I believe the answer is:
organisation
'running' is the definition.
('organisation' can be a synonym of 'running')
'over as rationing's broadcast' is the wordplay.
'over' becomes 'o' (cricket abbreviation**).
'broadcast' indicates anagramming the letters.
'as'+'rationing'='asrationing'
'asrationing' anagrammed gives 'rganisation'.
'o'+'rganisation'='ORGANISATION'
(Other definitions for organisation that I've seen before include "System" , "concern" , "Systematic approach to tasks" , "Running" .)