[nix.ie] n [G Nixe female nix, fr. OHG nichessa, fem. of nihhus nix] (1816): [4]nix
[2]nix.ie also nixy n, pl nix.ies [[1]nix + -ie] (ca. 1890): a piece of mail that is undeliverable because illegibly or incorrectly addressed Nix.ie trademark--used for an electronic indicator tube