This could eventually make a fine meal (5)
I believe the answer is:
grist
'meal' is the definition.
(I know that meal can be written as grist)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for grist that I've seen before include "what miller needs" , "Grain for grinding" , "seed corn" , "Ground grain" , "Corn [to the mill]" .)