Wikipedia
Untermensch (, underman, sub-man, subhuman; plural: Untermenschen) is a term that became infamous when the Nazis used it to describe "inferior people" often referred to as "the masses from the East", that is Jews, Roma, and Slavs (mainly ethnic Poles, Serbs, and later also Russians). The term was also applied to most Blacks, and persons of color, with some particular exceptions. Jewish people were to be exterminated in the Holocaust, while, according to the Generalplan Ost, the Slavic population of East-Central Europe was to be reduced in part through mass murder, with a majority expelled to Asia or used slave labor in the Reich. A few populations deemed partially "Aryan" in origin were to be Germanized (see kidnapping of children by Nazi Germany). These concepts were an important part of the Nazi racial policy. While the Nazis were inconsistent in the implementation of their policy, (mostly implementing the Final Solution while implementing Generalplan Ost the democidal death toll was in tens of millions of victims. It is related to the concept of life unworthy of life, a more specific term which originally referred to the severely disabled involuntarily euthanised in Action T4, and was eventually applied to the extermination of the Jews.