consent vs say-so

consent

noun
  • Voluntary agreement or permission. 

verb
  • To express willingness, to give permission. 

  • To cause to sign a consent form. 

  • To agree in opinion or sentiment; to be of the same mind; to accord; to concur. 

say-so

noun
  • Authority, as backing some statement, injunction, or command. 

How often have the words consent and say-so occurred in a corpus of books? (source: Google Ngram Viewer )