gnaw away at vs wear out

gnaw away at

wear out

verb
  • To punish by spanking. 

  • Of apparel, to display in public. 

  • To deteriorate or become unusable or ineffective due to continued use, exposure, or strain. 

  • To become exhausted, tired, fatigued, or weary, as by continued strain or exertion. 

  • To cause (something) to become damaged, useless, or ineffective through continued use, especially hard, heavy, or careless use. 

  • Of a shirt, to not tuck into the pants; to wear in a casual manner. 

  • To exhaust; to cause or contribute to another's exhaustion, fatigue, or weariness, as by continued strain or exertion. 

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