Top individual criminal in America (6)
I believe the answer is:
capone
'criminal in america' is the definition.
'capone' can be an answer for 'criminal' (I have seen 'Notorious criminal' mean 'capone' so perhaps 'criminal' could also mean 'capone'). I am not sure about the 'in america' bit.
'top individual' is the wordplay.
'top' becomes 'cap' (cap is a kind of top).
'individual' becomes 'one'.
'cap'+'one'='CAPONE'
Can you help me to learn more?
(Other definitions for capone that I've seen before include "Al ..., US gangster" , "Hood" , "Al - , notorious gangster" , "Notorious criminal" , "US gangster (St Valentine's Day massacre)" .)