Dach is a German word for "roof" and also happens to represent the world's three German speaking countries - Europeans are familiar with the acronyms on license plates - D for Deutschland (Germany), A for Austria and CH for Confederation Helvetica (Switzerland). It is also the name of the most toxic Hive community I currently know of.
Little correction, Dach does not represent the 3 countries, only the apronym in big Letter DACH or D-A-CH.