Naive don recollected a rocky time in past (8)
I believe the answer is:
devonian
'a rocky time in past' is the definition.
(geological era)
'naive don recollected' is the wordplay.
'recollected' indicates an anagram (letters recollected and rearranged).
'naive'+'don'='naivedon'
'naivedon' with letters rearranged gives 'DEVONIAN'.
(Other definitions for devonian that I've seen before include "From Exeter, perhaps?" , "West Country 11dn" , "West Country person" .)