Maize refers to a type of corn, specifically the common name for Zea mays. It is a staple food crop that originated in the Americas. The clue "Johnnycake grain" suggests that maize is used to make johnnycakes, which are a type of cornmeal flatbread or pancake.
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Johnnycake grain. Explanations are generated by AI and may be inaccurate.