Granola grains (4)
I believe the answer is:
oats
'granola grains' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for oats that I've seen before include "Sow wild ones in disreputable youth" , "Seed grasses" , "Hardy cereals eaten by horses" , "Cereal for porridge" , "Cereal grass and seeds" .)