No. Terrorism is the deliberate murder of civilians (or threats thereto), in order to advance a political objective.
It's not actually all that hard to define, some people just try to deliberately muddy the waters.
- The Columbine shootings were not terrorism since they had no political motive.
- The assassination of JFK was not terrorism since the President is not, for the purposes of this discussion, a "civilian" (I might need to work on the definition of "civillian")
- If a warplane drops a bomb aimed at a tank and it hits an orphanage by accident, that's not terrorism since the civilians weren't the actual target. (Note: that doesn't necessarily mean it was excusable).
- The Fort Hood massacre and the many attacks by Al Qaeda against US troops in Iraq and Afghanistan are not, strictly speaking, terrorism, since the targets are military rather than civilian (again this just a semantic distinction I'm making here, not a moral one).
Any other border cases we'd like to discuss? Note that by this definition terrorist attacks were commonly used by both sides in World War 2.