Formal:
* Region: This is the most general term and can be used for a large geographical area encompassing several districts.
* District: This term is more specific and refers to a smaller administrative area within a larger region.
* Area: This is a broad term that can encompass both districts and regions.
* Jurisdiction: This term is used to describe an area with specific administrative or legal boundaries.
* Territory: This term implies a defined area under the control of a government or other entity.
Informal:
* Neighborhood: This term is often used for a smaller, localized area within a larger district or region.
* Locality: This term is similar to "neighborhood" but can refer to a larger area.
* Zone: This term can be used for a distinct area with a specific purpose, such as a commercial zone or a residential zone.
Other options:
* Province: This term is used for a large administrative division within a country.
* State: This term is used for a larger political entity with its own government.
The best term to use depends on the specific context and the level of formality you require.