Cheerios ingredients
I believe the answer is:
oats
'cheerios ingredients' 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 "A cereal crop" , "Cereal grass and seeds" , "Wild ones are sown in youthful excess" , "Seed grasses" , "Grains or porridge" .)