Avoir bon dos is a French idiom that translates directly to “to have a good back” and means “to take the blame” or “be a convenient scapegoat”.
avoir bon dos
to take the blame
Example sentences
Both of these sentences uses the personal pronoun on, which has many usages. In the first sentence, on is used to mean “one” or “someone”. In the second sentence, on is used as a passive voice.
À chaque fois qu’on casse une assiette c’est moi qui ai bon dos!
Every time someone breaks a plate I’m the one who takes the blame!
Les étrangers ont bon dos : à chaque fois qu’il y a un problème dans la ville on les accuse.
Foreigners are convenient scapegoats. Every time there’s a problem in the city they get blamed.
Expression origin
The exact origin of this expression is unknown. Avoir bon dos (literally to have a good back) was originally used to describe somebody who could carry heavy loads. Later it came to describe somebody who was considered guilty even if they were innocent.