chew vs tear at

chew

verb
  • To grind, tear, or otherwise degrade or demolish something with teeth or as with teeth. 

  • To think about something; to ponder; to chew over. 

  • To crush with the teeth by repeated closing and opening of the jaws; done to food to soften it and break it down by the action of saliva before it is swallowed. 

noun
  • The condition of something being torn or ground up mechanically. 

  • The act of chewing; mastication with the mouth. 

  • Level of chewiness. 

  • A plug or wad of chewing tobacco; chaw or a chaw. 

  • A small sweet, such as a taffy, that is eaten by chewing. 

  • Chewing tobacco. 

tear at

verb
  • To afflict or aggrieve. 

  • To pull at violently. 

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