armor vs surety

armor

verb
  • To equip something with armor or a protective coating or hardening. 

  • To provide something with an analogous form of protection. 

noun
  • A protective layer over a body, vehicle, or other object intended to deflect or diffuse damaging forces. 

  • Metal plate, protecting a ship, military vehicle, or aircraft. 

  • A tank, or other heavy mobile assault vehicle. 

  • A military formation consisting primarily of tanks or other armoured fighting vehicles, collectively. 

  • A natural form of this kind of protection on an animal's body. 

  • The naturally occurring surface of pebbles, rocks or boulders that line the bed of a waterway or beach and provide protection against erosion. 

surety

noun
  • A promise to pay a sum of money in the event that another person fails to fulfill an obligation. 

  • One who undertakes to pay money or perform other acts in the event that his principal fails therein. 

  • A substitute; a hostage. 

  • Evidence; confirmation; warrant. 

  • Certainty. 

  • That which makes sure; that which confirms; ground of confidence or security. 

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