get at vs nark

get at

verb
  • To attack verbally or physically; to annoy, bother. 

  • To manage to gain access to. 

  • To understand or ascertain by investigation. 

  • To persuade by intimidation, to tamper with. 

  • To begin working on or dealing with. 

  • To contact someone. 

  • To mean, signify. 

nark

verb
  • To annoy or irritate. 

  • To stop. 

  • To serve or behave as a spy or informer. 

  • To complain. 

  • To watch; to observe. 

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

  • A police spy or informer. 

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