nixie

n. 1. See Nix. [ 1913 Webster ]

2. Nothing. [ Slang ] [ Webster 1913 Suppl. ]

3. (U. S. Mail Service) A piece of mail matter which cannot be delivered, either because no post office exists at the place to which is it addressed, or because there is no place of the name mentioned in the designated State, Territory, or the like. [ Cant ] [ Webster 1913 Suppl. ]