overman vs restrain

overman

verb
  • To provide with too many personnel; overstaff. 

noun
  • A person with great powers; a superman. 

  • A person who supervises others; a supervisor, especially in a mine. 

restrain

verb
  • To restrict or limit. 

  • To control or keep in check. 

  • To deprive of liberty. 

  • To strain again. 

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