safeguard vs surety

safeguard

noun
  • One who, or that which, defends or protects; defence; protection. 

  • A safe-conduct or passport, especially in time of war. 

  • Something that serves as a guard or protection; a defense. 

verb
  • To escort safely. 

  • To implement safeguarding. 

  • To protect, to keep safe. 

surety

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

  • 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. 

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