nixie means A female nix, a water-spirit. Lexicurio rates it Sui generis — a strength score of 87 out of 100.
nixie is pronounced /ˈnɪksi/.
Why “nixie” is a great word
NIXIE — [Noun] A female water-spirit in Germanic folklore, or a piece of mail returned to the sender as undeliverable. From German Nixe, feminine of Nix, from Middle High German nickes, from Old High German nihhus ("water-elf, crocodile"), from Proto-Germanic *nikwus, *nikwis, perhaps from Proto-Indo-European *neygʷ- ("to wash"). First recorded in English use in 1816, introduced by Sir Walter Scott. Unlike the Paracelsian undine, defined by alchemical lore, or the oceanic mermaid, a hybrid of woman and fish, a nixie is a shape-shifting, capricious presence in river and millpond. She is the pale flicker beneath a moonlit surface, the cold hand that could pull you under or push a child to shore, and the sodden envelope—address smeared, hope expired—that arrives back with a bureaucratic thud. Both are emissaries from a realm where messages are lost, and connections drown.
Etymology
From German Nixe, feminine of Nix, from Middle High German nickes, from Old High German nihhus (“water-elf, crocodile”), from Proto-Germanic *nikwus, *nikwis, perhaps from Proto-Indo-European *neygʷ- (“to wash”).
Cognate with Old English nicor (“water-elf, hippopotamus, walrus”), English nicker.
noun
- A female nix, a water-spirit.“The beautiful Nix or Nixie who allures the young fisher or hunter to seek her embraces in the wave which brings his death, the Neck who seizes upon and drowns the maidens who sport upon his banks, the river-spirit who still yearly in some parts of Germany demands tribute of human life, are all forms of the ancient Nicor[.]”
- A piece of mail returned as undeliverable.“Mailers who are registered participants in the Postal Service's Address Change Service (ACS) system expect to receive their address corrections and nixie notifications by electronic messages;[…].”