handcuff vs holdback

handcuff

noun
  • One ring of a locking fetter for the hand or one pair. 

verb
  • To apply handcuffs to 

  • to restrain or restrict. 

holdback

noun
  • The strap or part of the harness so used. 

  • The projection or loop, on the thill of a vehicle, to which a strap of the harness is attached, to hold back a carriage when going downhill, or in backing. 

  • restraint (act or result of holding back, device that restrains) 

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