The origin of the name Rosbach is still unknown. The town was named after the nearby stream () of the same name, obviously. The most accepted version of the origin of the word "Rosbach" itself is, that it is derived from the Middle High German "roezen" or "rozen" (; "to ret"). The most common craft in Rosbach was the weaving of linen and retting is used to describe the process of the separation of the fibre from the stem during the production of linen.