Genocide is the intentional destruction of a people in whole or in part. Raphael Lemkin coined the term in 1944, combining the Greek word γένος (genos, "race, people") with the Latin suffix -caedo ("act of killing").

In 1948, the United Nations Genocide Convention defined genocide as any of five "acts committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group." These five acts were: killing members of the group, causing them serious bodily or mental harm, imposing living conditions intended to destroy the group, preventing births, and forcibly transferring children out of the group. Victims are targeted because of their real or perceived membership of a group, not randomly.

The Political Instability Task Force estimated that 43 genocides occurred between 1956 and 2016, resulting in about 50 million deaths. The UNHCR estimated that a further 50 million had been displaced by such episodes of violence up to 2008. Genocide, especially large-scale genocide, is widely considered to signify the epitome of human evil. As a label, it is contentious because it is moralizing, and has been used as a type of moral category since the late 1990s.