'water-plantain' originates from Middle English, specifically the word 'water' combined with 'plantain', where 'water' referred to its aquatic habitat and 'plantain' referred to its broad leaves.

'water-plantain' changed from the Middle English word 'water plantain' and eventually became the modern English word 'water-plantain'.

Initially, it meant 'a plant growing in water with broad leaves', and this meaning has largely remained the same in modern usage.