A big city covers up major state of chaos (7)
I believe the answer is:
anarchy
'chaos' is the definition.
(I've seen this before)
'a big city covers up major state' is the wordplay.
'big city' becomes 'ny' (New York).
'covers up' indicates putting letters inside.
'major state' becomes 'arch' (I am not sure about this - if you are sure you should believe this answer much more).
'ny' going around 'arch' is 'narchy'.
'a'+'narchy'='ANARCHY'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for anarchy that I've seen before include "General disorder" , "Uncontrolled disorder" , "State of disorder in society" , "Lawlessness; chaos" , "Utter lawlessness" .)