courser vs retriever

courser

noun
  • A dog used for coursing. 

  • A person who practises coursing. 

  • Any of several species of bird in the genera Cursorius or Rhinoptilus of the family Glareolidae. 

  • A stone used in building a course. 

  • A racehorse or a charger. 

  • A hunter. 

retriever

noun
  • A type of gun dog that retrieves game for a hunter. 

  • A tool for retrieving materials from the body after an operation. 

  • One who retrieves something. 

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