It stands for knock.out.dead
so when you are completely and extremely tired and you are about to fall into a deep sleep as if you are dead
Girl 1: Hey girl, come shopping with me?!
Girl 2: Nah, i think ill give it a miss im about to k.o.d
Girl 1: Ok maybe next time, get some rest
King of Darkness, 10th album by independent rapper Tech N9ne, aka the best rapper ever.
Person 1: Have you heard Tech N9ne's new album K.O.D.?
Person 2: Yeah, that shit is fire!
Stands for: kids on drugs
You can use "kod" for an easier slang
Person 1- "Bro there's a whole lotta K.O.D"
Person 2- "That's facts"