Diablo 2 LOD term, short for naked kill. In dueling on Diablo 2 LOD, when you die, you come back to life in town and without gear. You must run out of town to retrieve your body, which is when NK occurs.
Teh only way j00 can EVER beat meh is to NK you fucking n00b.
Perfect ownage. Flawless victory. Schooled. Lesson taught. Owned beyond conventional words, and so excited about it, it's mistyped. Usually proceeded by noob.