noun
room with a raised floor
Refers to a traditional Japanese room where part of the floor is raised, often used for formal occasions or to seat a person of higher status.
この旅館には上段の間がある。
This ryokan has a room with a raised floor.
Compound of 上段 (raised floor) + の (possessive particle) + 間 (room). The exact historical derivation is uncertain, but the term is conventionally associated with traditional Japanese architecture.