How do you define terrorism?

The FBI says it’s investigating whether the mass shooting at a Sikh temple in Wisconsin is an act of domestic terrorism, but says it has yet to determine a motive. Today’s Question: How do you define terrorism?

sikh.jpg A police officer directs people near the Sikh Temple of Wisconsin after a gunman opened fire Aug., 5, 2012 Oak Creek, Wis. (Scott Olson/Getty Images)