downbear vs slack off

downbear

verb
  • To lessen; reduce. 

  • To bear or press down (on); press upon; depress; subdue. 

  • To bear, bring or carry down. 

slack off

verb
  • To decrease in intensity; to ease off; to diminish; to die down. 

  • To be deliberately unproductive in one's work or study. 

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