Definitions by Fed

YK 

To commit an unusually large, noxious, and possibly toilet-breaking bowel movement, usually in a public restroom or someone else's home.

Source: Internet fora.

"Man, don't go in there ... somone laid a YK!"

"Dude, I was on a date and I totally YK'd the chick's house."

YK by Fed March 9, 2005