denigrate vs take down a peg or two

denigrate

verb
  • To treat as worthless; belittle, degrade or disparage. 

  • To blacken. 

  • To criticise so as to besmirch; traduce, disparage or defame. 

take down a peg or two

How often have the words denigrate and take down a peg or two occurred in a corpus of books? (source: Google Ngram Viewer )