Delivery usually associated with an address in southern England? (8,13)
I believe the answer is:
received pronunciation
'address in southern england?' is the definition.
The definition suggests a singular noun which matches the answer.
'delivery usually associated with an' is the wordplay.
I cannot quite see how this works, but
'delivery' could be 'pronunciation' (I've seen this before) and 'pronunciation' is present in the answer.
'an' could be 'i' (Roman numeral for one) and 'i' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for received pronunciation that I've seen is " educated speech".)