knock on wood vs reproach

knock on wood

verb
  • To take a customary action to ward off some misfortune that is believed to be attracted by a presumptuous statement. 

intj
  • Hopefully; a self-directive to undertake the customary action to ward off bad luck. 

reproach

verb
  • To criticize or rebuke (someone). 

  • To disgrace, or bring shame upon. 

noun
  • A mild rebuke, or an implied criticism. 

  • Disgrace or shame. 

  • An object of scorn. 

How often have the words knock on wood and reproach occurred in a corpus of books? (source: Google Ngram Viewer )