antedate vs avert

antedate

noun
  • Prior date; a date antecedent to another which is the actual date. 

verb
  • To find earlier citational evidence for a term. 

  • To occur before an event or time; to exist further back in time. 

  • To assign a date to a document or action earlier than the actual date. 

avert

verb
  • To ward off, or prevent, the occurrence or effects of. 

  • To turn aside or away. 

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