Pronounced "dernk," but NEVER spelled with vowels, it can be traced back to stupid teenagers trying to come up with a sound that retarded people make. However, the true meaning of drnk lies in its context; you say this word when there is nothing to say.
It can be used in such situations as:
1. When something boggles your mind.
2. When you are completely confused as to what a teacher or other "authority" figure is speaking about and it all sounds like the "wa-waaa" noises the adults make in Peanuts.
3. When you've just witnessed a completely stupid act or heard a completely stupid joke.
4. Et cetera.
My friend Tom, after seeing the Matrix Reloaded: "The only way to adequately describe that movie would be a shiny, four-mile high DRNK."