American city encapsulating success and suffering (5)
I believe the answer is:
agony
'suffering' is the definition.
(synonyms)
'american city encapsulating success' is the wordplay.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'city' becomes 'ny' (short for New York).
'encapsulating' indicates putting letters inside (I've seen this in other clues).
'success' becomes 'go' (I've seen this in other clues).
'a'+'ny'='any'
'any' going around 'go' is 'AGONY'.
'and' is the link.
(Other definitions for agony that I've seen before include "Extreme pain" , "Really severe pain" , "Suffering - anguish" , "Pain, torment" , "Torture" .)