corn a general name for cereal crops, is also commonly used in the USA and elsewhere as a name for maize. The latter usage is especially prevalent with regard to the kinds of maize eaten as vegetables; the terms ‘sweet corn’ and ‘corn on the cob’ are examples. But maize is a single species, and is considered in all its forms in the entry for it. That entry includes, at the end, references to various products and preparations whose names incorporate the word ‘corn’.
Corn in the wide sense crops up in the Bible and in expressions such as corn-fed, corn exchange, cornfield.