dirty dog. A scoundrel; a despicable person.
Dogs are notoriously dirty. Bring your pet home from getting a professional grooming and you will likely find him or her heading straight for something unsavory to roll in, just to get rid of that clean smell.
In the romance novel Savannah there is really only one despicable character, Osmond Kott, who is described as a ”dirty dog,” though the name is then withdrawn by the genteel persons who otherwise inhabit the book.
Pearsall, Judy, and Bill Trumble. 1996. The Oxford English Reference Dictionary. 2d ed. Oxford, New York: Oxford University Press.
2. Price, E. 1983. Savannah. 1st ed. Garden City, N.Y.: Doubleday, 166.