swear vs vow

swear

verb
  • To take an oath, to promise intensely, solemnly, and/or with legally binding effect. 

  • To promise intensely that something is true; to strongly assert. 

  • To take an oath that an assertion is true. 

  • To use offensive, profane, or obscene language. 

  • To be lazy; rest for a short while during working hours. 

  • To administer an oath to (a person). 

adj
  • Dull; lazy; slow. 

  • Top-heavy; too high. 

  • Reluctant; unwilling. 

  • Heavy. 

  • Niggardly. 

noun
  • A swear word. 

  • A lazy time; a short rest during working hours (especially field labour); a siesta. 

vow

verb
  • To make a vow; to promise. 

  • To declare publicly that one has made a vow, usually to show one's determination or to announce an act of retaliation. 

  • To make a vow regarding (something). 

noun
  • A solemn promise to perform some act, or behave in a specified manner, especially a promise to live and act in accordance with the rules of a religious order. 

  • A declaration or assertion. 

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