bird dog vs ferret

bird dog

verb
  • To seek out. 

  • A multiservice tactical brevity code requesting configuration of sensors. 

  • To watch closely. 

noun
  • A dog, especially a pointer, used in shooting to retrieve the dead birds. 

  • A tout. 

  • A person who seeks out real estate investment opportunities in exchange for a fee. 

  • A person who tries to steal someone else's romantic partner 

  • A radar detector (for detecting police speed traps). 

  • A hyperextension exercise performed lying on the knees, with one arm and the opposite leg lifted. 

ferret

verb
  • To uncover and bring to light by searching; usually to ferret out. 

  • To hunt game with ferrets. 

noun
  • A diligent searcher. 

  • An often domesticated mammal (Mustela putorius furo) rather like a weasel, descended from the polecat and often trained to hunt burrowing animals. 

  • The black-footed ferret, Mustela nigripes. 

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