shogun's council chamber; Edo castle governmental affairs room
Historical term referring to the room in Edo Castle where the shogun's council of elders (老中) conducted official business.
The council chamber was located in the main keep of Edo Castle.
The elders gathered in the council chamber to discuss important shogunate policies.
Compound of 御用 (goyō, 'official business') + 部屋 (heya, 'room'), referring to the governmental affairs room in Edo Castle.