Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!

Qenya 

nelle

noun. brook, brook, *stream

A noun in The Etymologies of the 1930s glossed “brook” derived from primitive ᴹ✶nenle (Ety/NEN), where the ancient nl became ll (PE19/47).