'earthnut' originates from Old English, specifically the word 'eorþnutu', where 'eorþ' meant 'earth' and 'nutu' meant 'nut'.

'eorþnutu' transformed into the Middle English word 'erthenote', and eventually became the modern English word 'earthnut'.

Initially, it meant 'a nut growing in the earth', but over time it evolved into its current meaning of 'a type of tuber or root vegetable'.