noble's private quarters
Refers to the inner residential area of a noble's residence, especially in historical contexts such as the Edo period.
江戸城の奥御殿は大奥とも呼ばれた。
The inner palace of Edo Castle was also called the Ōoku.
Compound of 奥 (oku, 'inner part') and 御殿 (goten, 'palace' or 'noble residence').