bird dog vs nark

bird dog

verb
  • To watch closely. 

  • A multiservice tactical brevity code requesting configuration of sensors. 

  • To seek out. 

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. 

nark

verb
  • To watch; to observe. 

  • To stop. 

  • To annoy or irritate. 

  • To serve or behave as a spy or informer. 

  • To complain. 

noun
  • An unpleasant person, especially one who makes things difficult for others. 

  • A police spy or informer. 

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