Past times (10)
I believe the answer is:
yesteryear
'past times' is the definition.
(synonyms)
This is all the clue.
(Other definitions for yesteryear that I've seen before include "Former times" , "Rossetti's translation questioned whereabouts of its snows!" , "Period 14 [CENTENARIAN] lived through" , "Time disappeared" , "Days gone by" .)