How would you write "Battle of Unnumbered Dead" in elvish?

How would you write "Battle of Unnumbered Dead" in elvish? Sindarian or Quenyan, it doesn't really matter which. Thank you sincerely so much!

Imariele!

Hello Severus,

In Sindarin I would suggest Dagor i·Ñgyrth Arnediad.

I am unsure about your intention with "imariele", it doesn't seem like an Elvish word to me.

Greetings Ellanto,

Thank you so much for the help with the Sindarin translation! I am sincerely grateful!

As for Imarielle, I thought it was an Elvish word for goodbye, but I have not checked my LOTR books to make sure.

Kind Regards,

Severus