knock down vs sleep over

knock down

verb
  • To approve a drinking toast by banging glasses on the table. 

  • To drink fast. 

  • To disassemble for shipment. 

  • To reduce the price of. 

  • To hit or knock (something or someone), intentionally or accidentally, so that it falls. 

  • To demolish. 

  • At an auction, to declare (something) sold with a blow from the gavel. 

sleep over

verb
  • To spend the night as a guest in someone's home. 

How often have the words knock down and sleep over occurred in a corpus of books? (source: Google Ngram Viewer )