door separating inner and outer castle areas (Edo period)
A specific architectural term from the Edo period, referring to a door or gate that divided the inner citadel (honmaru) from the outer citadel (ninomaru) in Japanese castles. Not used in modern everyday language.
The o-jōguchi of Edo Castle was an important gate separating the honmaru and ninomaru.
Compound of 御 (o-, honorific prefix) + 錠 (jō, 'lock') + 口 (kuchi, 'opening, entrance'). The exact historical derivation is uncertain, but the term refers to a lockable passageway in Edo-period castle architecture.