Clausen is not a city in Germany. Based on available records, it is primarily recognized as a Danish patronymic surname. The name literally translates to "child of Claus," with Claus being a German form of the Greek name Nikolaos.
The surname has been used in Denmark since at least the 16th century. While it is common in Denmark and the Schleswig-Holstein region, occurrences outside these areas are typically attributed to immigration. In some instances, immigrants to English-speaking countries have modified the spelling of the name to Clauson.