A massacre is a killing, typically of multiple victims, considered morally unacceptable, especially when perpetrated by a group of political actors against defenseless victims. The word is a loan of a French term for "butchery" or "carnage".
There is no objective definition of what constitutes a "massacre". Various international organisations have proposed a formal definition of the term "crimes against humanity", which would however include incidents of persecution or abuse that do not result in deaths. Conversely, a "massacre" is not necessarily a "crime against humanity". Other terms with overlapping scope include war crime, pogrom, and mass murder.
The modern definition of massacre as "indiscriminate slaughter, carnage", and the subsequent verb of this form, derive from late 16th century Middle French, evolved from Middle French "macacre, macecle" meaning "slaughterhouse, butchery." Further origins are dubious, though may be related to Latin macellum "provisions store, butcher shop."
The Middle French word macecre "butchery, carnage" is first recorded in the late 11th century. Its primary use remained the context of animal slaughter (in hunting terminology referring to the head of a stag) well into the 18th century. The use of macecre "butchery" of the mass killing of people dates to the 12th century, implying people being "slaughtered like animals". The term did not necessarily imply a large number of victims, e.g. Fénelon in Dialogue des Morts (1712) uses l'horride massacre de Blois ("the horrid massacre at [the chateau of] Blois") of the assassination of Henry I, Duke of Guise (1588), while Boileau, Satires XI (1698) has L'Europe fut un champ de massacre et d'horreur "Europe was a field of massacre and horror" of the European wars of religion.