corroborate vs rule out

corroborate

verb
  • To make strong; to strengthen. 

  • To confirm or support something with additional evidence; to attest or vouch for. 

rule out

verb
  • To make something impossible. 

  • To reject an option from a list of possibilities. 

  • To disallow. 

  • To cross an item out by drawing a straight line through it, as with a ruler. 

  • To make unavailable. 

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