1 the act or an instance of departing.
2 (often foll. by from) a deviation (from the truth, a standard, etc.).
3 (often attrib.) the starting of a train, an aircraft, etc. (the departure was late; departure lounge).
4 a new course of action or thought (driving a car is rather a departure for him).
5 Naut. the amount of a ship's change of longitude.
Etymology: OF departeuumlre (as DEPART)
Useful english dictionary. 2012.