This week’s term isn’t Dutch at all, it’s German. Hollandgänger literally means Holland-goer. It’s a German term to describe seasonal workers who would come to the Netherlands to work.
They’d walk to the Netherlands in spring, work here all summer, and then return to their families in Germany in the autumn. Most of these people were poor farm laborers from Westphalia, Münsterland, Osnabrück, or East-Friesland.
Some of these workers met their partners in the Netherlands and stayed here. Most Dutch people have German ancestors somewhere in their trees.