Thing of the past (5)
I believe the answer is:
relic
'thing of the past' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for relic that I've seen before include "Item surviving from the past" , "Reminder of times past" , "Survivor from the past" , "Memorial of saint" , "Surviving artefact" .)