1. The fact of living in a place.
2. The official residence of the Governor General's representative or another government agent, especially at the court of an Indian state.
3. An organization of intelligence agents in a foreign country.
4. A musician's regular engagement at a club or other venue.
5. A period of specialized medical training in a hospital; the position of a resident.
Plural Noun: Residencies
The whole residency is mountainous.