Merriam-Webster’s online dictionary gives the origin of the word “eldritch” as “perhaps from Middle English *elfriche fairyland, from Middle English elf + riche kingdom, from Old English rīce — more at rich.”
I like that. Fairyland. Elf kingdom. Eldritch.
Sometimes we modern types forget how eerie the fae are, how scary traditional fairy lore can be. This word eldritch has some horror connotations because of H.P. Lovecraft and his “eldritch horror.” But the ancient lore is pretty frightening, too.
For example, I remember reading in Evans-Wentz’s Fairy Faith In Celtic Countries a story about a human midwife who was called to the birth of a fairy child. Later, she was wearing fairy ointment (a magical potion you put on your eyelids so you can see the fae in their true forms). She had the ointment on only one eye (can’t remember why that was). She went to a market or fair, and as she was wandering around she noticed the man who’d hired her for the fairy birth.
He noticed her looking at him and approached her, asking which of her eyes could see him. She pointed to the eye with the ointment. He reached out and touched that eye, and she went permanently blind there.
Another fairy, called the Fool, or Amadan na Briona (sp? it’s Gaelic) can drive you to insanity with a single touch.
These are not Tinkerbell fairies.