Happens when a nerd is rotating their xbox 360 controller joystick so violently, they actually get a burn in the center of their hand. Similar to carpet burn, but on a much nerdier, less skanky scale.
Nerd: Do you mean your Ethernet cord? You couldn't fit a T1 line in a bag!
Nerds within earshot: *laughter* Ohhhh! Nerd Burn!
Cool Guy: Yeah right! Just admit it. We all know that you got nerd-burn. *Laughs*
Obama: "If you think you can overturn my veto, try it."
America: "NERD BURN!"