noun
west building; western annex
Refers to a building or wing located on the west side of a complex, such as a hospital, school, or shopping center.
病院の西館は外来受付です。
The west building of the hospital is for outpatient reception.
デパートの西館にはレストラン街がある。
There is a restaurant area in the department store's west annex.
Compound of 西 (west) and 館 (building, hall).