approbation vs consent

approbation

noun
  • The act of approving; an assenting to the propriety of a thing with some degree of pleasure or satisfaction; approval, sanction, commendation or official recognition. 

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. 

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