Dirty German Share definition Flag n. A "moustache" given to another person by applying moustache wax to a finger in secret, then dragging the waxed finger across the person's upper lip. See: Dirty Sanchez "I like the way your moustache smells." "Do you want a Dirty German?" Dirty German by Helmut Kohl July 3, 2007 Get the Dirty German mug.