"Terrorism" comes from the French word terrorisme,[12] and originally referred specifically to state terrorism as practiced by the French government during the Reign of terror. The Jacobins cited this precedent when imposing a Reign of Terror during the French Revolution.[14][15] After the Jacobins lost power, the word "terrorist" became a term of abuse.[8] Although "terrorism" originally referred to acts committed by a government, currently it usually refers to the killing of innocent people[16] by a non-government group in such a way as to create a media spectacle.
The definition of terrorism has proved controversial. Various legal systems and government agencies use different definitions of terrorism in their national legislation. Moreover, the international community has been slow to formulate a universally agreed, legally binding definition of this crime.
Among the various definitions there are several that do not recognize the possibility of legitimate use of violence by civilians against an invader in an occupied country.[citation needed]
Barack Obama, commenting on the Boston Marathon bombings of April, 2013, declared "Anytime bombs are used to target innocent civilians, it is an act of terror."[43]
The terms "terrorism" and "terrorist" (someone who engages in terrorism) carry strong negative connotations.[44] These terms are often used as political labels, to condemn violence or the threat of violence by certain actors as immoral, indiscriminate, unjustified or to condemn an entire segment of a population.[45] Those labeled "terrorists" by their opponents rarely identify themselves as such, and typically use other terms or terms specific to their situation, such as separatist, freedom fighter, liberator, revolutionary, vigilante, militant, paramilitary, guerrilla, rebel, patriot, or any similar-meaning word in other languages and cultures. Jihadi, mujaheddin, and fedayeen are similar Arabic words which have entered the English lexicon.