kaffir vs spook

kaffir

noun
  • A black person. 

  • South African mining shares 

  • A member of the Nguni people of southern Africa, especially a Xhosa. 

  • A language spoken by the Nguni peoples of southern Africa, especially Xhosa. 

  • In Islamic contexts, a non-Muslim. 

spook

noun
  • A psychiatrist. 

  • A ghost or phantom. 

  • An undercover agent or spy. 

  • A hobgoblin. 

  • A scare or fright. 

  • A player who engages in hole carding by attempting to glimpse the dealer's hole card when the dealer checks under an ace or a 10 to see if a blackjack is present. 

  • A metaphysical manifestation; an artificial distinction or construct. 

verb
  • To frighten or make nervous (especially by startling). 

  • To become frightened (by something startling). 

  • To haunt. 

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