beagle vs supergrass

beagle

noun
  • A person who snoops on others; a detective. 

  • A bailiff. 

  • A small kind of shark. 

  • A small short-legged smooth-coated scenthound, often tricolored and sometimes used for hunting hares. Its friendly disposition makes it suitable as a family pet. 

verb
  • To search. 

  • To hunt with beagles. 

supergrass

noun
  • An informer providing substantial quantities of information on criminal or terrorist activities to the police. 

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