basement king 

Someone who is successful at a video game (or similar activity) in local play or within their circle of friends, but is easily defeated by actual good players. The term is most likely based on the typical horizontally-arranged tier system, in which the lowest tier is the " basement ", and the best player of that tier is it's " king ".

" I dominated Dale at Street Fighter last night, his basement king status has been revealed. "

basement king by Kripto January 11, 2016

basementing 

The act of sitting in a basement and doing nothing. Most commonly this is found in a group of friends who are boring and have nothing else to do, or are too lazy to get off their asses and make something of their lives. Basementing is the opposite of adventure.

Yo, you want to go over to Chris'?
nah bro they're just basementing again.
lets go climb a mountain and go basejumping.
YEA!

basementing by the real patyfatycake February 20, 2011