This is a fantastic word! I like it so much I want to go back and add it to the story I just finished. (More on that later.) It is defined as follows by Apple dictionary:
eldritch |ˈeldri ch |
adjective
weird and sinister or ghostly : an eldritch screech.
ORIGIN early 16th cent. (originally Scots): perhaps related to ELF.
How can I possibly be such a big fan of Tolkien and not know this word? No matter—it’s mine now!