To some extent, it’s a long-forgotten beauty spot? (5)
I believe the answer is:
salon
'beauty spot?' is the definition.
(I've seen this in another clue)
'to some extent it's a long-forgotten' is the wordplay.
'to some extent' says the answer is hidden in the clue (I've seen 'extent of' mean this (I've seen this in other clues)).
'SALON' is hidden in the letters of 'its a long forgotten'.
(Other definitions for salon that I've seen before include "Loans out as a reception room" , "Hairdresser's establishment" , "Hairdresser's shop" , "Parisian art exhibition" , "Establishment of beauty specialist or hairdresser" .)