Underworld slang broadcast absorbing European ruffian on bike (5,5)
I believe the answer is:
hells angel
'ruffian on bike' is the definition.
'underworld slang broadcast absorbing european' is the wordplay.
'underworld' becomes 'hell' ('Hell' can be a synonym of 'underworld'**).
'broadcast' indicates anagramming the letters.
'absorbing' is an insertion indicator.
'european' becomes 'e' (abbreviation e.g. EU).
'slang' anagrammed gives 'sangl'.
'sangl' going around 'e' is 'sangel'.
'hell'+'sangel'='HELLS ANGEL'
(Other definitions for hells angel that I've seen before include "gang member" , "Aggressive biker" , "Tough biker" .)