In 1934, Ernst Fraenkel, professor of Baltic languages at the University of Kiel, argued that the name "Judeich" derives from the Lithuanian word "JUODEIKA". The Lithuanian origin seems to be quite logical, since the first ancestors lived in Insterburg, which is only 60 km away from Lithuania. But what does "juodeika" mean? The word consists of two parts: "JUODAS" which translates into "black" and "EIKA" which is a common ending of Lithuanian surnames. Fraenkel translates the name with "black person". The first person who was called "Judeich" must therefore somehow be connected to the color black. He or she may have had black hair, dark skin or may have liked to dress in black. When the name was translated into German, the ending "-a" was dropped, and the harsh sounding "-k" was changed into a softer sounding ending "-ch".
In 2004, the society for name research of the University of Leipzig confirmed Fraenkel's interpretation. But a second possible interpretation of the name was given, too. The name could also derive from the Lithuanian word "JUODEIKIS", which can be translated into "black-sour soup" (blood soup). The first Judeich may have been able to prepare this soup very well or may just have enjoyed the soup very much. Thus, two interpretation of the name "Judeich" exist. But both have a common origin - the color black.