bachelor vs frater

bachelor

noun
  • A bachelor apartment. 

  • Someone who has achieved a bachelor's degree. 

  • The first or lowest academical degree conferred by universities and colleges; a bachelor's degree. 

  • A person, especially a man, who is socially regarded as able to marry, but has not yet. 

  • A kind of bass, an edible freshwater fish (Pomoxis annularis) of the southern United States. 

frater

noun
  • A frater house. 

  • A monk. 

  • A comrade. 

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