Si vs Sizhou

Si

name
  • Various prefectures of imperial China. 

  • A diminutive of the male given name Simon. 

  • A river in Shandong, China. 

  • A diminutive of the male given name Silas. 

  • A county in Anhui, China. 

Sizhou

name
  • A subprefecture of Jiangnan, in Qing-era China 

  • A prefecture of Shanxi, in imperial China 

  • A town in Sizhou prefecture, Shanxi, in imperial China 

  • A town in Sizhou, Jiangnan, in Qing-era China 

How often have the words Si and Sizhou occurred in a corpus of books? (source: Google Ngram Viewer )