hdk
"High, don't know."

Used in place of idk ("I don't know") when the reason you do not know something is a direct result of being high. It generally implies that you actually do know, but are too lazy to give it enough thought to remember.
Sam: What was the name of that band we just saw before we smoked this marijuana?
Joe: hdk, "The Rivets" or "Five Rivers" or "Space Remote" or something...