From the distant past (7)
(Other definitions for olden that I've seen before include "Of a former age" , "Bygone" , "of ancient history?" , "(Of days) in the long distant past!" , "Led on (anag)" .)
'from the distant past' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for ancient that I've seen before include "Very old, like some civilizations" , "Old man" , "Archaic" , "Very old, like the poetic mariner" , "Bygone" .)