gnaw away at vs tatter

gnaw away at

tatter

noun
  • A shred of torn cloth; an individual item of torn and ragged clothing. 

  • A person engaged in tatting. 

verb
  • To fall into tatters. 

  • To destroy an article of clothing etc. by shredding. 

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