Decadent city in which anything goes (7)
I believe the answer is:
naughty
'decadent city in which anything goes' is the definition.
Both the definition and answer are adjectives. Perhaps you can see a link between them that I don't see?
'decadent city in which anything' is the wordplay.
'decadent city' becomes 'ny' (short for New York. I am not sure about the 'decadent' bit.).
'in which' indicates putting letters inside.
'anything' becomes 'aught' ('aught' means anything).
'ny' placed around 'aught' is 'NAUGHTY'.
Can you help me to learn more?
(Other definitions for naughty that I've seen before include "Badly behaved, child say" , "Behaving badly or risque" , "Wicked" , "Badly behaved, mischievous" , "Badly-behaved" .)