in the four seas and nine regions -- in the whole country
The synonym sihaijiuzhou generally refers to jiuzhousihai, Chinese idioms, Pinyin is Ji ǔ zh ō us ì h I, meaning still speak the world, generally refers to the whole of China. It's from the song of Dengfeng.
The origin of Idioms
In Tang Dynasty, Lu Zhaolin's song of Dengfeng, it is said that "nothing happens in Jiuzhou and all over the world, and you will be happy forever."
Idiom usage
Used as an object or attribute; used in writing. However, it is pure and virtuous, and the imperial court has a great discussion on it. Wang Anshi's Xianggong book of the upper Song Dynasty
everywhere
a thousand things wait to be done - bǎi fèi dài xīng
one's blood boils with indignation - rè xuè fèi téng
handle complicated matters with ease - jǔ zhòng ruò qīng
suffer affronts without resentment - shǔ fù jī cháng
No one in the court should be an official - cháo lǐ wú rén mò zuò guān