departure — Departure or a departure is the act of going away from somewhere.
emigration — The act of emigrating; movement of a person or persons out of a country or national region, for the purpose of permanent relocation of residence.
flight — an act or instance of fleeing or running away; hasty departure.
evacuation — The action of evacuating a person or a place.
exit — A way out, especially of a public building, room, or passenger vehicle.