A fork of Rural Dictionary
un sale rat de merde is basically a shitty human being, or a snitch. the biggest example is gaston, he's the rat king.
frr gaston c'est un sale rat de merde
A "sale merde" is someone like Edouard Faesch or Xavier Gasser, people who are des sales merdes
Edouard est une sale merde, ca c'est sûr !