Noted runners from previous era hurrying back (5)
I believe the answer is:
hares
'noted runners' is the definition.
The answer and definition can be both animals as well as being plural nouns.
Perhaps you can see an association between them that I don't see?
'from previous era hurrying back' is the wordplay.
'from' indicates the answer is hidden within the clue.
'back' shows that the letters should be reversed in order.
'serah' is hidden in the letters of 'previous era hurrying'.
'serah' in reverse letter order is 'HARES'.
(Other definitions for hares that I've seen before include "Fleet-footed animals" , "Rabbit-like creatures" , "Swift long-eared mammals" , "Share of wild animals" , "Fast-running animals" .)