corroboration vs repudiation

corroboration

noun
  • That which corroborates. 

  • The act of corroborating, strengthening, or confirming; addition of strength; confirmation 

repudiation

noun
  • The act of refusing to accept; the act of repudiating. 

  • The young man's repudiation of the church's doctrines caused a conflict with his religious parents. 

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