Basement Ninja
A person(usually a teenager) who rarely sees the light of day and spends his time playing videogames ranging from: Modern Warfare 2 to World of Warcraft.
Example:
Me: Dude, I was enjoying a casual game of Modern Warfare 2 when this 10th Prestige dropped into my game and fucked everyone up.
Friend: What a fuckin Basement Ninja.
Me: Dude, I was enjoying a casual game of Modern Warfare 2 when this 10th Prestige dropped into my game and fucked everyone up.
Friend: What a fuckin Basement Ninja.