cheapening vs nosedive

cheapening

noun
  • The process by which something is cheapened or made vulgar. 

nosedive

noun
  • A rapid fall, e.g. in price or value. 

  • A headfirst fall or jump. 

  • A drop in altitude with the nose of the craft angled downwards. 

verb
  • To dive down in a steep angle. 

  • To perform a rapid fall in price or value. 

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