An evacuation is when people leave a place quickly and safely because they need to get away from danger or something bad.
When there's an emergency like a fire, flood, or natural disaster, authorities often order an evacuation. This means that people have to pack their bags, gather any essential things, and move out of the area as soon as possible. This is usually done for everyone's safety, so they can get to a safer place until the danger passes.
How common is "evacuation"?
Word evacuation is considered uncommon in modern English. It has a balanced usage among all categories: speech, fiction, newspapers and academic texts.
Definitions
noun
The act of evacuating; leaving a place in an orderly fashion, especially for safety.
Withdrawal of troops or civils from a town, fortress, etc.
The act of emptying, clearing of the contents, or discharging, including creating a vacuum.
Voidance of any matter by the natural passages of the body or by an artificial opening; defecation; also, a diminution of the fluids of an animal body by cathartics, venesection, or other means.
That which is evacuated or discharged; especially, a discharge by stool or other natural means.