General:
* Departure: This is the most common and straightforward noun for "depart."
* Leaving: This is more informal and can be used in place of "departure" in some contexts.
* Going away: This is another informal option, usually used in more casual settings.
More Specific:
* Exit: This emphasizes the act of physically leaving a place.
* Evacuation: This implies a sudden or urgent departure due to danger or emergency.
* Migration: This implies a movement of people or animals from one place to another, often for seasonal reasons.
* Flight: This refers specifically to the act of leaving by air.
* Voyage: This refers to a long journey by sea.
The best noun to use will depend on the specific situation and the intended meaning.