/kɔːrn/
[noun] A grain or seed, or a plant that produces grain. In North America it usually means maize, while in Britain it can refer to wheat, barley, or other cereal crops.
Before Europeans ever saw maize, 'corn' simply meant any grain — so 'corn' in the Bible has nothing to do with America.
The word 'corn' is one of the oldest in the English language, descending from the Proto-Germanic word *kurnam, which meant a small, hard seed or grain. This ancient root is closely related to the Latin word granum, meaning grain, and both share a Proto-Indo-European ancestor *gr̥nom, a word that described a worn-down or ground particle — evoking the idea of something small and hard that could be crushed into powder. From Proto-Germanic *kurnam, the word passed into Old English as corn, where it meant any grain or seed used for food, most commonly wheat or barley in the British Isles.
For most of its history in English, 'corn' was a general, catch-all word for whatever grain was most important to a given region. In England it typically meant wheat. In Scotland and Ireland it usually referred to oats, because oats grew better in those cooler, wetter climates. In the Bible, when Joseph stores up 'corn' in Egypt, the translators simply used the word that their English-speaking readers would understand as the staple grain — almost certainly describing barley or emmer wheat, not the tall American plant we picture today.
Everything changed in 1492. When Columbus arrived in the Americas, Europeans encountered a tall, flowering plant with large, jewel-like seeds clustered on a cob — a crop that Native peoples had been cultivating for thousands of years. Spanish explorers called it maíz, borrowing from the Taíno word mahiz. When English settlers arrived in North America in the 1600s, they encountered this same plant. Because they needed a familiar word for the most important grain of the new land, they applied their existing word: corn. What had once meant any grain now began to shift, in American English at least, toward meaning this one very specific grain.
Back in Britain, the word held on to its older, broader meaning. British English still uses 'corn' to refer generally to cereal crops — which is why the famous 'Corn Laws' of 19th-century Britain regulated the trade of wheat and barley, not maize. This split between British and American usage is one of the clearest examples of how the same word can travel in two completely different directions once a language separates across an ocean. The same divergence gave us 'biscuit,' 'chips,' and 'football' — but 'corn' may be the most vivid example of all.
The word has also branched into surprising corners of everyday English. A 'kernel' — the inner seed of any grain or nut — comes from the same Old English root, passing through Old English cyrnel, a diminutive form meaning 'little corn.' The phrase 'corn of salt' — now most often heard as 'grain of salt' — preserved the old, broad meaning of corn as any tiny granule. Even 'unicorn' is unrelated, coming instead from Latin uni- (one) and cornu (horn) — though cornu and corn do share that ancient Proto-Indo-European root, both tracing back to the idea of something hard, pointed, and small.