blackball vs sit-down

blackball

noun
  • A rejection; a vote against admitting someone. 

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

  • 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. 

verb
  • To ostracize. 

  • To vote against, especially in an exclusive organization. 

sit-down

noun
  • A sit-in, a protest of civil disobedience by people sitting and refusing to move. 

  • An act of sitting down, especially with other people in some form of social exchange. 

adj
  • Intended to be done, used, consumed etc. while sitting. 

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