avow vs vow

avow

verb
  • To bind or devote by a vow. 

  • To declare openly and boldly, as something believed to be right; to own, acknowledge or confess frankly. 

  • To acknowledge and justify, as an act done. See avowry. 

vow

verb
  • To make a vow regarding (something). 

  • 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; to promise. 

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 avow and vow occurred in a corpus of books? (source: Google Ngram Viewer )