Gangster covered in blood abundantly (6)
I believe the answer is:
galore
'abundantly' is the definition.
(thesaurus)
'gangster covered in blood' is the wordplay.
'gangster' becomes 'al' (Al Capone).
'covered in' indicates putting letters inside.
'blood' becomes 'gore' ('gore' can be a synonym of 'blood').
'al' going within 'gore' is 'GALORE'.
(Other definitions for galore that I've seen before include "'Whisky ------!', classic Ealing comedy of 1949" , "Aplenty" , "Lo, Reg, a change could be in abundance" , "In profusion" , "abundantly" .)