1.  interj. no.  The man said nix, and he means nix.  
2.  exclam. No!; Stop it!; I disagree! (Usually Nix!)  “Nix,” said Paul. “I can’t permit that.”  
3.  n. nothing.  I got nix for a tip. And after I was so helpful!  
4.  tv. to put a stop to something; to say no to something; to ban something; to turn something down.  I wanted to say a certain word in my speech, but the management nixed it.