1 (Noun): A mark on clothing/material etc whcih is very difficult/impossible to remove.
2 Somebody who is just always there and won't go away; is often well known for being around your area and can't be gotten rid of. Most of what they do annoys one.
A cocaine fiend who is constantly up and if not is always looking for drugs.
A person who you can rely on to have/bring cocaine to any social gathering, regardless how big or small.
Guy 1: "Hey look at Josh doing cocaine with that guy he doesn't even know."