(historical) The inner chamber (inner quarters) of the Edo Castle where the shōgun's consort, concubines, and ladies in waiting resided. Other than the shōgun, no other men were permitted entrance. Male children were raised in Ooku until the age of 7 at which time they had to move out and reside in other parts of the castle.

a place name, such as that of Oita Prefecture or Oita City

a lot / a majority

a surname

(Shinto) a grand ritual to give thanks to the gods after the enthronement of the Emperor

at every possible opportunity

(of time) every

including; up to; entirely

Nominalizer for an action.

仕事: work, occupation, employment