Nope. First off, it doesn't cover the USS Cole (which was not crewed by "random civilians"). Second, it doesn't necessarily require violence (e.g. the threat of violence; leaving a bomb threat on an airliner with intent to disrupt operations is a form of terrorism.) Thirdly, the aim isn't the physical act of killing civilians, it's the psychological effect that terrorism aims for (it just so happens that the most effective way to mess with someone's psychology is to kill a bunch of people, but killing isn't required). Fourth, "fear and despair" is overly narrow...hell, my points six through eight cover deficiencies in that last clause as well, so let me just restate it: "...with the aim of applying effective pressure to a defined group or society by any means deemed practical."
Killing is just the practical means to that end. Terrorist groups don't just kill for ***** and grins; their behavior is highly goal-directed, something that your definition doesn't recognize.