central building; central wing
Refers to the main or central building of a complex, such as a library, museum, or hospital. Often part of a proper name.
The library's central building is near the station.
This museum is divided into the central wing and the east wing.
Compound of 中央 (central) and 館 (building, hall). The exact historical derivation is uncertain, but the word follows a common pattern for naming institutional buildings.