boost vs knock down

boost

verb
  • To steal. 

  • To lift or push from behind (one who is endeavoring to climb); to push up. 

  • To give a booster shot to. 

  • To help or encourage (something) to increase or improve; to assist in overcoming obstacles. 

  • To amplify; to signal boost. 

  • To jump-start a vehicle by using cables to connect the battery in a running vehicle to the battery in a vehicle that won't start. 

noun
  • A positive intake manifold pressure in cars with turbochargers or superchargers. 

  • A coordinate transformation that changes velocity. 

  • A push from behind, as to one who is endeavoring to climb. 

  • Something that helps, or adds power or effectiveness; assistance. 

knock down

verb
  • To demolish. 

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

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

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