Cereal and Indian corn

Cereal noun - Grass whose starchy grains are used as food: wheat; rice; rye; oats; maize; buckwheat; millet.

Indian corn and cereal are semantically related in maize topic. In some cases you can use "Indian corn" instead a noun "Cereal".

Indian corn noun - Tall annual cereal grass bearing kernels on large ears: widely cultivated in America in many varieties; the principal cereal in Mexico and Central and South America since pre-Columbian times.

Cereal and Indian corn are semantically related in maize topic. You can use "Cereal" instead a noun phrase "Indian corn".