Basically, its when you get hit by a grenade and die in Counterstrike
OMFG I GOT NADED AGAIN BY TEH SAME GUY TAHT HAS TEH UBER 1337 HAX!!!!1111!1
Bah, he naded me.
To be hit in the balls or cunt punted.
Comes from the word Gonad.
He got naded.