Re: 24d
The 4 lettered answer is used in Britain as a general word for cereal crops. I was brought up on an English farm, and this is the general word used for fields of wheat, barley or oats. The even more general term “arable” is maybe better known, but refers to a broader type of land use for growing crops for people or animals to eat.
In the UK, the answer word on its own is not used to refer to sweet**** or maize (a fodder crop version) but in a culinary context is contained in the term ****flour. I imagine that when early British settlers saw **** in the Americas, they just used the general term that they knew, hence the American usage of the word today, and the international confusion.... I live in the US, and the church choir was singing a Harvest hymn by the British composer John Rutter that contained this word preceded by “waving fields of” (or similar - from memory), and that confounded the American singers!