curb vs shackle

curb

noun
  • Something that checks or restrains; a restraint. 

  • A swelling on the back part of the hind leg of a horse, just behind the lowest part of the hock joint, generally causing lameness. 

  • A concrete margin along the edge of a road; a kerb (UK, Australia, New Zealand) 

  • A riding or driving bit for a horse that has rein action which amplifies the pressure in the mouth by leverage advantage placing pressure on the poll via the crown piece of the bridle and chin groove via a curb chain. 

  • A sidewalk, covered or partially enclosed, bordering the airport terminal road system with adjacent paved areas to permit vehicles to off-load or load passengers. 

  • A raised margin along the edge of something, such as a well or the eye of a dome, as a strengthening. 

verb
  • To rein in. 

  • To bend or curve. 

  • To furnish with a curb, as a well; to restrain by a curb, as a bank of earth. 

  • To crouch; to cringe. 

  • To damage vehicle wheels or tires by running into or over a pavement curb. 

  • To check, restrain or control. 

  • To bring to a stop beside a curb. 

shackle

noun
  • A restraint on one's action, activity, or progress. 

  • A link for connecting railroad cars; a drawlink or draglink. 

  • A length of cable or chain equal to 12+¹⁄₂ fathoms or 75 feet, or later to 15 fathoms. 

  • A U-shaped piece of metal secured with a pin or bolt across the opening, or a hinged metal loop secured with a quick-release locking pin mechanism. 

  • A fetter-like band worn as an ornament. 

  • A restraint fit over a human or animal appendage, such as a wrist, ankle or finger; normally used in pairs joined by a chain. 

verb
  • To render immobile or incapable; to inhibit the progress or abilities of. 

  • To shake, rattle. 

  • To restrain using shackles; to place in shackles. 

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