heighten vs pejorate

heighten

verb
  • To make high; to raise higher; to elevate. 

  • To advance, increase, augment, make larger, more intense, stronger etc. 

pejorate

verb
  • To make or become worse; to deteriorate or to worsen. 

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