cheapen vs deprave

cheapen

verb
  • to make vulgar 

  • to become cheaper 

  • to decrease the value of; to make cheaper 

deprave

verb
  • To speak ill of; to depreciate; to malign; to revile 

  • To make bad or worse; to vitiate; to corrupt 

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