Seat of famous oracle in Philadelphia (6)
I believe the answer is:
delphi
'seat of famous oracle' is the definition.
The definition and answer can be both locations as well as being singular nouns.
Maybe there's an association between them I don't understand?
'in philadelphia' is the wordplay.
'in' says the answer is hidden in the clue.
'DELPHI' is hidden within 'philadelphia'.
Can you help me to learn more?
(Other definitions for delphi that I've seen before include "Old Greek city" , "Place of Greek oracle" , "Ancient Greek city, site of famous oracle" , "Greek site of Apollo's most famous oracle" , "Where god used to speak" .)