According to Merriam-Webster’s Dictionary, Terrorism is defined as follows:
the systematic use of terror especially as a means of coercion
Oxford takes it a bit further:
The unlawful use of violence and intimidation, especially against civilians, in the pursuit of political aims
And finally, the Urban Dictionary brings it all home:
Manipulation of any person or group of persons fear (the emotion of terror, hence TERRORism) in order to gain obedience/forceful agreement, or accomplish a certian objective.
-So there’s that.