corroboration vs disavowal

corroboration

noun
  • That which corroborates. 

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

disavowal

noun
  • A denial of knowledge, relationship, and/or responsibility towards something (or someone). 

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