degrade vs tarnish

degrade

verb
  • To lower in value or social position. 

  • To reduce in altitude or magnitude, as hills and mountains; to wear down. 

  • To reduce in quality or purity. 

tarnish

verb
  • To lose its lustre or attraction; to become dull. 

  • To compromise, damage, soil, or sully. 

  • To oxidize or discolor due to oxidation. 

noun
  • Oxidation or discoloration, especially of a decorative metal exposed to air. 

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