blackball vs endorse

blackball

verb
  • To ostracize. 

  • To vote against, especially in an exclusive organization. 

noun
  • A black ball used to indicate such a negative vote. 

  • A rejection; a vote against admitting someone. 

  • A kind of large black sweet; a niggerball. 

  • A game, a standardized version of the English version of eight-ball. 

  • A substance for blacking shoes, boots, etc. or for taking impressions of engraved work. 

endorse

noun
  • A diminutive of the pale, usually appearing in pairs on either side of a pale. 

verb
  • To report (a symptom); to describe. 

  • To write one's signature on the back of a cheque, or other negotiable instrument, when transferring it to a third party, or cashing it. 

  • To express support or approval, especially officially or publicly. 

  • To give an endorsement. 

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