The long river that flowed southward from Nenuial was called Baranduin by the Elves, a name that meant approximately 'golden brown river'. When the Hobbits settled in the Shire during the Third Age, a part of this river formed their new eastern border, and they took a name modelled on the original Elvish: Branda-nîn, meaning 'border-water'.

In the playful, punning character of the Hobbits, though, the river's name evolved over time to become Bralda-hîm, relating to its golden brown colour and meaning 'heady ale'. This later name became the ultimate source of Tolkien's anglicised version of the Hobbit-name, which is Brandywine.