One thing in my mind will be more clear with Book 13 tho; Names of places in Forochel map was a bit strange to other places we got used to (which often sindarin or common tongue is used), can we assume they are "local" tongue of Lassoths? Shall we have a little bit more information of their meanings?
They are somewhat modified Finnish (which is the culture Tolkien based the Lossoth on.) The modifications are mostly making double vowels a single long vowel.