NaK

Okay kiddo, "nak" is not actually a word, but it's short for "no ammo knife," which is a term people use in video games like Call of Duty.

When you have no ammo left for your gun, instead of reloading, some players switch to their knife because it doesn't require ammo. So "nak" is a quick way to let your teammates know that you don't have ammo and you're using your knife instead.

It's just a simple way of communicating in the game, so you and your team can work together better. Pretty cool, right?