phonetically pronounced ('badz), the acronym stands for Boot And Dump Stain. It is created when one person projectile vomits and defecates upon another person (presumably in retaliation for some offense), creating an unmistakable residue. Often, receiving a B.A.D.S. will induce one to vomit and/or defecate upon oneself. It is the ultimate insult in any situation.
Just once I'd love to give my boss the ol' B.A.D.S., before I quit.