Castor vs Slave

Castor

name

  • One of the Dioscuri 

  • A village and civil parish in city of Peterborough district, Cambridgeshire, England (OS grid ref TL1298). 

  • A double star in the constellation Gemini; alpha (α) Geminorum. 

  • A village in Bienville Parish, Louisiana, United States. From French castor (“beaver”). 

  • A town in Alberta, Canada. From French castor (“beaver”). 

  • A surname. 

Slave

name

  • Synonym of Sclavia 

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