Discontented attendant encounters bridal parties in capital city (6)
I believe the answer is:
athens
'capital city' is the definition.
(capital of Greece)
'discontented attendant encounters bridal parties' is the wordplay.
'discontented' suggests removing the centre (the word's contents are removed).
'encounters' means one lot of letters go next to another.
'bridal parties' becomes 'hens' (I can't explain this - if you can you should give a lot more credence to this answer).
'attendant' with its centre removed is 'at'.
'at'+'hens'='ATHENS'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for athens that I've seen before include "Mediterranean capital" , "Site of the Parthenon" , "City in which 13 Across founded school" , "EU capital" , "Greek capital" .)