embolden vs restrain

embolden

verb
  • To render (someone) bolder or more courageous. 

  • To encourage, inspire, or motivate. 

  • To format text in boldface. 

restrain

verb
  • To restrict or limit. 

  • To control or keep in check. 

  • To deprive of liberty. 

  • To strain again. 

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