Cereal is a noun.
Cereal is a grain like wheat or maize used for food, or the grass that produces this grain, or the breakfast food made from this grain, which is usually taken with milk.
Cereal originated from a Latin word, Ceres, meaning Roman Goddess of agriculture.
The little girl had milk and cereals while her mother ate hamburger.
In Hindu religion when a person fasts, he/she is not supposed to eat anything made of cereals.