Curse, "cobweb," "witch," "ghost," and even "Halloween" - all of these potentially spooky words have roots in Old English. "Eldritch," also, comes from a time when otherworldly beings were commonly thought to inhabit the earth. The word is about 500 years old and believed to have come from Middle English "elfriche," meaning "fairyland." The two components of "elfriche" - "elf" and "riche" - come from the Old English "ælf" and "rīce" (words which meant, literally, "elf kingdom"). Robert Louis Stevenson wasn't scared of "eldritch." He used the term in his novel Kidnapped: "'The curse on him and his house, byre and stable, man, guest, and master, wife, miss, or bairn -- black, black be their fall!' -The woman, whose voice had risen to a kind of eldritch sing-song, turned with a skip, and was gone."