To keep nix is an old english boarding school term for keeping a lookout. It is thought to derive from the word that was shouted by said lookout when a housemaster or teacher approached. Younger boys were instructed to "keep nix" while the older boys smoked, drank, buggered each other etc etc.
"I say Jenkins, will you keep nix while I roger young perkins there!"
"Nix!"
"Quick run here comes Mr Cooke"
By Cherida
Nix
Used when something is more than lit. The phrase refers to a Pheonix being reborn out of flames, you take nix out of pheonix and get nix.
Guy: Brooo that party was lit! A firecracker almost blew off Lady Gaga's wig and I won 40,000 dollars!
Guy 2: Nah, man. That shit-- that shit was nix.
By Cassandra
Nixe
A variation of the english word "nice" meant to sharpen its sound and make it more meaningful and less superficial.