blot out vs revalidate

blot out

verb
  • Used other than figuratively or idiomatically: see blot, out. 

  • To obscure. 

  • To annihilate 

  • To make indecipherable; to obliterate. 

revalidate

verb
  • To validate again. 

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