Flame of Udûn

[Eowyn Skywalker]

I am sorry if this topic has been done before, but I searched, and didn't find what I wanted.

In the Fellowship of the Ring, Gandalf shouts at the Balrog: "Go back to the shadow. The Dark Fire will not avail you, flame of Udûn!"

Now, from what I know about Elvish, Udûn means 'West'. West was the good lands of Middle-earth, and to the Undieing Lands. Obviously, Gandalf was calling the Balrog: flame of Udûn.

Was this meant to be an insult? And if so, why was this an insult, if the West was the good lands?

That's my question, and no one I know can answer it, and I haven't found anything on this exact topic on Barrowdowns yet. If this has been covered, please give me the link, and I will be happy to move.

If not, well then I hope that there are people who understand what Tolkien meant here.

Anar kaluva tieyanna.

-Eowyn Skywalker

Im pretty sure that "numen" is the word for west isnt it? Anyway Udun is another name for Utmuno, Melkor/Morgoths first fortress. It also basically means hell. So Gandalf is saying "Go back to the shadow flame of Hell" which Im pretty sure is an insult.

[Lalaith]

From the encyclopaedia of arda:

'Flame' is a reference to its nature as a fire-demon, while 'Udûn' was the name of Morgoth's oldest and greatest fortress in the north of the World, more commonly called Utumno, and the Balrog's ancient home.
There is no direct connection between this 'Udûn' and the rounded valley to the northwest of Mordor with the same name. There is an indirect connection, though: that region also took its name from the stronghold of Sauron's master.