What is "umvolkung"

Umvolkung (an artificial German term echoing Umpolung "polarity inversion", as it were translating to "ethnicity inversion") is a term in Nazi ideology used to describe a process of assimilation of members of the German people (the Volk) so that they would forget about their language and their origin.

The term is also utilized to describe the "re- Germanisation" of the German people, after new Lebensraum was conquered and the German people who already resided there would become more German again. Of course, Umvolkung in the first sense was seen as a negative process during the Third Reich, while the second process was seen as desirable.