act of terrorism

act intended to cause injury and fright to citizens (often carried out by an extremist political organization)

Terrorism in the modern sense is violence or other harmful acts committed (or threatened) against civilians for political or other ideological goals. Most definitions of terrorism include only those acts which are intended to create fear or "terror", are perpetrated for an ideological goal (as opposed to a lone attack), and deliberately target or utterly disregard the safety of non-combatants. Many definitions also include only acts of unlawful violence.
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Noun
1. the calculated use of violence (or threat of violence) against civilians in order to attain goals that are political or religious or ideological in nature; this is done through intimindation or coercion or instilling fear
(synonym) terrorism, terrorist act
(hypernym) coercion
(hyponym) bioterrorism, biological terrorism