avow vs front up

avow

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

  • To bind or devote by a vow. 

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

front up

verb
  • To admit or confess. 

  • To show up; to appear or present oneself. 

  • To lead or represent. 

  • To meet with one's best efforts. 

  • To face; to confront or challenge. 

  • To pay in advance or give with the expectation of being reimbursed later. 

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