A term borrowed from French, used as either a noun or verb, referring to the killing of a "significant number” of (at least five) persons in a single event, whereas victims are undefended, or have little capability of defending themselves relative to their attacker(s).
 From Old French macecre or macecle, meaning slaughter, derived from the verb macecler / macecrer (massacrer), also in its 12th Century form: maçacre. Its origins may be either from the Arabic maslakh (مسلخ), also meaning to butcher, or to skin, or from the Latin vulgate matteuculare, derived from gallo-roman matteuca..
 Rocio Mezquita, "The Guatemalan Commission for Historical Clarification: Data Processing,” in Patrick Ball, Herbert F. Spirer, and Louise Spirer, eds. Making the Case: Investigating Large Scale Human Rights Violations Using Information Systems and Data Analysis (Washington: AAAS, 2000); Eric Carlton, "Race, Massacre and Genocide: An Exercise in Definitions,” International Journal of Sociology and Social Policy, Vol. 10, No. 2 (1990), 80–93. The United Nations Office of the High Commissioner for Human Rights refers to a massacre as an act of killing three or more persons. OHCHR, Human Rights and Law Enforcement: A Manual on Human Rights training for Police (Professional Training Series No. 5) (Geneva: OHCHR, 1997).
 The foregoing definition is based on the application of the term in human rights, humanitarian law and criminal contexts. More generally, the Oxford English Dictionary defines "massacre” as, “The indiscriminate and brutal slaughter of people or (less commonly) animals; carnage, butchery, slaughter in numbers.” The first known use of the term in the English language refers to events in France known as the Saint Bartholomew’s Day Massacre (Massacre de la Saint-Barthélemy), in which an estimated 5,000 to 30,000 victims were killed. A long but incomplete list of events commonly referred to as "massacres” is found at: http://en.wikipedia.org/wiki/List_of_massacres#cite_ref-OED_N_0-0.