withdrawal — Also, withdrawment. the act or condition of withdrawing.
flight — an act or instance of fleeing or running away; hasty departure.
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.
abandonment — The abandonment of a place, thing, or person is the act of leaving it permanently or for a long time, especially when you should not do so.