Terrorism is an act of inducing terror as a means to achieving a goal.
Terrorism works by exploiting fears. It is most important to note that if there are no fears, there can be no terrorism.
Considering the above wide definition, let's take a look at some examples which fit under this definition:
Horror movies are an example of honest terrorism. You pay for a 'terror vaccine', the experience of mild terror for the enjoyment of knowledge and observation of your fears.
If horror movies are a 'terror vaccine', news are a 'terror drug'. The media exploits the public's desire to experience fear by being selective and blowing out of proportion.
For a consumerist society to exist as such, 'need' (a special kind of fear) has to be present. When marketing moves from providing information to propaganda of need, it commits terrorism.
Combine science, marketing, and existential fear. What do you get? A more thorough marketing terrorism.
'Corporate terrorism' may cover a variety of meanings: a small group terrorizing a corporation, a corporation terrorizing another corporation, a corporation terrorizing itself, or a corporation terrorizing a small group or individual. Plenty of possibilities here.
Police states are the epitome of terrorism; terrorism so complete that heavily influences the reality-perception of subjects - and even perception of self-identity.
Suicide bombers are the traditional image of terrorism. Usually misguided in achieving their goal, but they sure leave a lot of impact on the media - used and abused for various purposes.
Random killings are product of psychological and social pressure; an act of lashing out against without a clearly defined goal. A visible and fearful symptom of an unhealthy society, it leaves a forceful impact not only because of the apparent lack of goal, but also because of blatant disregard of personal identity.
Find a fear, and you'll also find a way to abuse it.