piss dirty

It's when someone fails a piss drug test.

Term used for when you have illict substance(s) in your system and in situation where as you are drug tested, you would not pass to say the least. Can also be expressed as saying "pissing dirty" which can be quite hysterical if used in question context in reference to another pass time activity as something fun to do with a little slang (not including proper verbage or grammar).