avouch vs say no

avouch

verb
  • To acknowledge deliberately; to admit; to confess; to sanction. 

  • To declare freely and openly; to assert. 

  • To confirm or verify, to affirm the validity of. 

  • To appeal to; to cite or claim as authority. 

say no

verb
  • To reject something. 

  • To disagree; to think something or someone is doing or saying what is wrong. 

How often have the words avouch and say no occurred in a corpus of books? (source: Google Ngram Viewer )