Terrorism (noun)

1. The use of violence and intimidation in the pursuit of political aims.
2. The use of terror as a means of coercion.
3. The systematic use of terror, especially as a means of coercion.

Origin:

The word terrorism comes from the french word "terrorisme" which is derived from the latin word "terror" which means fear or dread.

Examples:

1. The terrorist attack on the World Trade Center was an act of terrorism.
2. Terrorism is a major threat to world peace.
3. The government is taking steps to combat terrorism.
4. Terrorism is a form of unconventional warfare.
5. Terrorism is a serious problem that affects us all.