pivot hinge cavity; door pivot socket
Historical architectural term for the upper and lower cavities in a door frame that receive the pivot of a traditional Japanese door. Not used in modern everyday language.
See also: 枢 (くるる)
Archaic metonymic use where the pivot part stands for the whole door. Extremely rare; modern Japanese uses 戸 or 扉.
In old Japanese houses, 枢 (とぼそ) were used to receive the pivot of a door.
In classical literature, 枢 can be used simply to mean 'door'.