The international community still doesn't have a working definition that is accepted by other countries. In fact, the US doesn't even have a single definition of terrorism, not that they haven't tried come up with one.
Defense Department: Terrorism is the unlawful use or threatened use of force or violence against individuals or portoperty to coerce or initmidate governmentsor socieities, often to achieve politicial religious, or ideological objects
Defense Intelligence Agency: Terrorism is premeditated, political violence perpetrated against noncombatant targetss by subnational gourps or clandestine state agents, usually to influence an audience.
FBI: IS the unlawful use of force or violence against persons or propterty to intimitadate or coerce a government, the civilian population, or any segment theroef, in furtherance of political or social objectives.
State Department: Premeditated, politically motivated violence perpetratated against noncombatant targets by subnational groups or clendestine agents, usually intended to influence an audience.
Jonathan White, Terorrism & Homeland Security, 2003.