What does "keep nix" mean?
Good evening,folks!
Yesterday I was reading James Joyces's short story Eveline and I came upon this word "nix" in the second paragraph:
"Her father used often to hunt them in out of the field with his blackthorn stick;but usually little Keogh used to keep nix and call out when he saw her father coming..."
What does "keep nix" mean here?
I'm wondering whether the word is still in use today?
Many thanks in advance!

Question

What does "keep nix" mean? 
Good evening,folks!
Yesterday I was reading James Joyces's short story Eveline and I came upon this word "nix" in the second paragraph:
"Her father used often to hunt them in out of the field with his blackthorn stick;but usually little Keogh used to keep nix and call out when he saw her father coming..." 
What does "keep nix" mean here?
I'm wondering whether the word is still in use today?
Many thanks in advance!

Answer

From urbandictionary.com:
"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""

Answer

This phrase is not used in (American) English, at least I have never heard it.