martinet vs oppressor

martinet

noun
  • A strict disciplinarian. 

  • Anyone who lays stress on a rigid adherence to the details of discipline, or to forms and fixed methods or rules. 

  • A martin; a swift. 

oppressor

noun
  • Someone who oppresses another or others. 

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