A term made popular by the classic television series "Blackadder II", meaning canine excrement, or dog shit.
E: If I die, Baldrick, do you think people would remember me?
B: Yeah. People would always be slapping each other on the shoulders and laughing, and saying "Do you remember old Privy-breath?"
E: Do people call me "Privy-breath"?
B: Yeah, the ones who like you.
E: Am I then not popular?
B: Erm, well, put it this way: when people slip in what dogs have left in the street, they do tend to say "Whoops, I've trod on an Edmond."
- Blackadder II, Episode 4: "Money".