Some Mafioso hoodlums in New York district (4)
I believe the answer is:
soho
'new york district' is the definition.
'soho' can be an answer for 'district' (I have seen 'District of London ' mean 'soho' so perhaps 'district' could also mean 'soho'). I'm unsure of the 'new york' bit.
'some mafioso hoodlums in' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'SOHO' can be found hidden inside 'mafioso hoodlums in'.
Can you help me to learn more?
(Other definitions for soho that I've seen before include "Smoke's part" , "Central London or Manhattan district" , "Colourful show-biz area of West End London" , "Theatre and night-life district of London" , "Call a large market for software" .)