a Naziconcentration camp in Germany during World War II. See also Auschwitz in this glossary.Naziconcentration camp in WestGermany during World War II. This and similarNazi camps such as Auschwitz were the sites for detention of many millions who the Nazis labelled undesirable (most notably the bulk of the Jews of Europe). More than six million people were eventually exterminated in these camps. Those who were not killed outright were ill treated, many subjected to cruel experimentation and torture, and great masses died of disease or starvation.the name of one of the many concentration camps run by the Nazis during World War II (1939-1945). Belsen was established in 1943 in northernGermany for holding prisoners-of-war as well as Jews. Although built to accommodate only 10,000 prisoners, by the end of the war it was housing more than 40,000. The camp had some of the most horrific livingconditions of any, with tens of thousands of prisoners dying from starvation, disease and overwork. It was the first camp to be liberated by the British Army in April 1945 and was burned down shortly thereafter.