Maize and Popcorn

Maize 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.

Popcorn and maize are semantically related. In some cases you can replace term "Popcorn" with "Maize", this nouns are similar.

Popcorn noun - Corn having small ears and kernels that burst when exposed to dry heat.

Maize and popcorn are semantically related. You can use "Maize" instead a noun "Popcorn".