Source : Webster's Revised Unabridged Dictionary (1913)

Terrorism \Ter"ror*ism\, n. [Cf. F. terrorisme.]
   The act of terrorizing, or state of being terrorized; a mode
   of government by terror or intimidation. --Jefferson.

Source : WordNet®

terrorism
     n : 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
         [syn: {act of terrorism}, {terrorist act}]