Comment by legitster

From Wikipedia:

"Terrorism, in its broadest sense, is the use of violence against non-combatants to achieve political or ideological aims. The term is used in this regard primarily to refer to intentional violence during peacetime or in the context of war against non-combatants."

There's a lot of disagreement about the international definition of terrorism, but most seem to agree that it is specifically violence against non-combatants and outside the context of a declared military action.