Bags containing last of autumn's nuts, perhaps (6)
I believe the answer is:
snacks
'nuts perhaps' is the definition.
(nuts are a type of snack)
'bags containing last of autumn's' is the wordplay.
'bags' becomes 'sacks' (sack is a kind of bag).
'containing' is an insertion indicator.
'last of' says to take the final letters.
The final letter of 'autumn' is 'n'.
'sacks' enclosing 'n' is 'SNACKS'.
(Other definitions for snacks that I've seen before include "Small food amounts between main meals" , "Light informal meals" , "Small or casual meals, often hurried" , "Nibbles" , "Light repasts" .)