Byzantines knew them as “royal nut”. For Germanic speakers is a “Welsh nut” because it came from Italy through France. We are just talking about walnuts. “Wal” referred to any person speaking foreign language, Romance or Celtic. Romance languages just call it “nut” and so it did South Slavic people. Among the rest of Slavic languages, there is a divide between the “Italian nut” in the West and the “Greek nut” in the East. In North America are called “English Walnuts” despite the fact that they were brought into the United States by Spanish missionaries.
In 1280 Marco Polo saw for the first time a strange big nut in Sumatra. The Arabs already knew it and called it jawz hindī (جوز هندي), which the Italian explorer translated literally to Latin as nux indica, the Indian nut. This name is still present in many languages (yellow on the map).
Two centuries later the explorer Vasco da Gama created a new name much more exotic: Coco. Because it resembles the traditional Portugues Jack-o’-lantern, a pumpkin with three holes, that represents the face of a mythical monster, similar to the bogeyman. The word coco might refer to the head or the skull. Then in Europe some languages added the nut, however botanically speaking, this fruit is a drupe, not a true nut.
The languages in violet are unique roots. For example, Dutch Klappernoot was borrowed from Indonesian kelapa . Indonesia was colonized by the Netherlands and it is also one of the regions where coconuts are originally from.
Some small languages have great names: In Manx is called Nut Milk (Cro Bainney). Coconut milk is a milky-white liquid extracted from the grated pulp. In Moksha is sea nut (иневедень пяште, ineveden’ pjašte). Because coconuts are light and water-resistant, they disperse via marine currents. It is said that they can travel 110 days or 5,000 kilometers. Thanks to both characteristics coconuts played a key role in the early migrations of the Austronesian peoples, and later, for the commercial routes to Africa the Caribean.
The cashew tree (Anacardium occidentale) is a tree connected to Portugal. This tropical evergreen tree is not originally from there, however. It grew in the northeast of modern Brazil, back then a Portuguese colony of Portugal. For this reason, Azerbaijani call it “Brazilian nut”.
On the other hand, some languages (on the map colored in green) say “Indian nut”. This is because between 1560 and 1565 cashew nuts were shipped to another Portuguese colony, Goa, where the weather conditions are similar. It spread all over the Indian subcontinent and other parts of Southeast Asia, where it became part of the traditional cuisine: for example, the liquor Feni and the Philipino sweet Turrones de casuj. Later it was taken to West Africa and finally to East Africa.
Its products are the cashew apple (an accessory fruit or pseudofruit), but especially the cashew seed, called cajú or acajú. Portuguese explorers took the name from Old Tupi acajú, which translates as “the fruit that produces itself”, and bring it to Europe.
However, not all languages adopted the original name. Often body organ metaphors are used: Lithuanian and many Romance languages also use the scientific name form Greek anakardia (ἀνάκαρδία), meaning “on/upon the heart”, due to the heart-shaped pseudofruit. Polish, on the other hand, do not see any heart but a kidney, orzech nerkowca means “kidney-shaped”.