hip-hop vs knap

hip-hop

verb
  • To perform hip-hop music. 

  • To move by hopping or with a hopping motion. 

noun
  • An Afro-American urban youth culture based on rap music, breakdancing etc. 

  • A form of popular and dance music featuring strong percussion and a powerful rhythm, usually accompanied by rapping. 

knap

verb
  • To rap or strike sharply. 

  • To shape a brittle material having conchoidal fracture, usually a mineral (flint, obsidian, chert etc.), by breaking away flakes, often forming a sharp edge or point. 

  • To make a sound of snapping. 

noun
  • A protuberance; a swelling; a knob. 

  • A small hill 

  • A sharp blow or slap. 

  • The crest of a hill 

How often have the words hip-hop and knap occurred in a corpus of books? (source: Google Ngram Viewer )