In his Appendix to The Silmarillion, Christopher Tolkien explains the element esgal- as 'screen, hiding', but doesn't explain why this would apply to the Esgalduin. It would be natural to associate the name with Doriath's being known as the 'Hidden Kingdom', but in fact this does not seem to be correct. Actually, the Esgalduin seems to have taken its name from the dense forests it ran through, whose branches and leaves veiled the river from sight. This interpretation comes from The Etymologies (The History of Middle-earth volume V, The Lost Road and Other Writings III). |