Literal translation: “cheek whistle face” / meaning: someone whose face makes you want to punch him
Backpfeifengesicht is a perfect example of creativity in German insults. It is highly effective, yet politically correct and innocent enough to not have you bleeped out.
Moreover, it is one of the rare swear words that not only describe the person you want to offend but literally tells a story in itself. It consists of the parts Backpfeife and Gesicht. The latter simply means “face,” the first describes a specific kind of slap. Backpfeife is already a gem of a word. Literally, it translates to “cheek whistle.” So when you give someone a Backpfeife, you hit him on his cheek so hard that he hears a whistle in his ears.
So if we go back to Backpfeifengesicht, the word describes a person that you want to hit with a tinnitus-inducing punch just by looking at his visage. What an excellent way to express your disrespect towards someone.