east building; eastern annex
Refers to a building or wing located on the east side of a complex, such as a school, hospital, or office.
病院の東館は外来受付です。
The east building of the hospital is the outpatient reception.
博物館の東館には特別展示があります。
There is a special exhibition in the east wing of the museum.
Compound of 東 (ひがし, 'east') and 館 (かん, 'building' or 'hall'). The reading ひがし is the native Japanese word for 'east', and かん is the on'yomi of 館.