Anglicized version of the German machts nichts (literally: makes nothing) meaning makes no difference. Used by soldiers stationed in Germany to describe something unimportant or a chore or small detail. Example: Jay cleaned out most of the junk in the garage. Now all that's left is some mox-nix stuff.
NOX-NIX
Meaning of NOX-NIX in English
Slang English vocab. Английский сленговый словарь. 2012