fetter vs leg irons

fetter

noun
  • A chain or similar object used to bind a person or animal – often by its legs (usually in plural). 

  • Anything that restricts or restrains. 

verb
  • To restrain or impede; to hamper. 

  • To shackle or bind up with fetters. 

leg irons

noun
  • A fetter or shackle attached at the ankle. 

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