noun
Imperial Family; Imperial Household
Refers to the Japanese imperial family as an institution or lineage. Formal and historical in tone; in modern contexts, 皇室 (こうしつ) is more common.
帝室の伝統は長い歴史を持っている。
The traditions of the Imperial Family have a long history.
その宝物はかつて帝室の所有物だった。
That treasure was once the property of the Imperial Household.