befriend vs blacklist

befriend

verb
  • To favor. 

  • To become a friend of, to make friends with. 

blacklist

verb
  • To place on a blacklist; to mark a person or entity as one to be shunned or banned. 

noun
  • A list or set of people or entities to be shunned or banned. 

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