Area chief stopping New York's state of lawlessness (7)
I believe the answer is:
anarchy
'state of lawlessness' is the definition.
(I've seen this before)
'area chief stopping new york's' is the wordplay.
'area' becomes 'a' (maths abbreviation).
'chief' becomes 'arch' (synonyms).
'stopping' indicates putting letters inside (inserted letters stop or plug a gap).
'new york' becomes 'ny'.
'arch' placed into 'ny' is 'narchy'.
'a'+'narchy'='ANARCHY'
(Other definitions for anarchy that I've seen before include "State of civil disorder" , "State of disorder in society" , "Utter lawlessness" , "Absence of government" , "Society without government or law, chaos" .)