Definitions by Vicious Dix

Reninja 

When you revoke an invite or take back a gift out of spite. Similar terms include "indian giver".

Girl: "Your social calendar seems to be pretty full so i'll give you back next Friday. No need to come to my Christmas party."
Boy: "What? Seriously?"
Girl: "Yep"
Boy: "Reninja"

Reninja by Vicious Dix December 21, 2008