grass up vs squeal

grass up

verb
  • To betray by informing on. 

squeal

verb
  • To give sensitive information about someone to a third party; to rat on someone. 

  • To make a squealing noise. 

  • To scream with a shrill, prolonged sound. 

noun
  • A high-pitched sound, such as the scream of a child or a female person, or noisy worn-down brake pads. 

  • The cry of a pig. 

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