demean vs downgrade

demean

verb
  • To mortify. 

  • To debase; to lower; to degrade. 

  • To subtract the mean from (a value, or every observation in a dataset). 

  • To humble, humble oneself; to humiliate. 

noun
  • resources; means. 

  • demesne. 

downgrade

verb
  • To disparage. 

  • to reduce the official estimate of a storm's intensity. 

  • To reduce in complexity, or remove unnecessary parts; to dumb down. 

  • To place lower in position. 

  • To revert software back to an older version. 

noun
  • A reduction of a rating, as a financial or credit rating. 

  • A downhill gradient on a road or railway. 

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