Слово "cereal". Англо-русский словарь Мюллера

            Rusanov had already noticed Shulubin's arrogant opinion on matters of agriculture. He had been explaining something about cereals when Shulubin had interrupted the conversation and corrected him.

"Snack bars", expecting to get the box of cereal bars he'd bought before departing for Hogwarts.

perhaps it affects the cereal we buy in the grocery store,

Tracy had learned a good deal about cooking from Charles, and she was tempted by the varieties of foodstuffs on the warden's shelves, but Amy preferred a simple breakfast of oatmeal or cereal with fruit.