cave in vs knockdown

cave in

noun
  • The act of something collapsing or caving in. 

  • The act of relenting. 

  • The location where something has caved in. 

verb
  • To collapse inward or downward. 

  • To relent; to grant approval against one's initial will. 

knockdown

noun
  • An act of knocking down or the condition of being knocked down. 

  • The condition of a sailboat being pushed abruptly to horizontal, with the mast parallel to the water surface. 

  • A shelter erected for use as a temporary dressing room. 

  • A collection of parts required to assemble a product, typically manufactured in one region and exported elsewhere for assembly. 

  • a short pass played downwards, for example from the head onto someone's feet. 

  • A genetically modified organism that carries one or more genes in its chromosomes that have been made less active or had their expression reduced. 

  • The use of a reagent such as an oligonucleotide with sequence complementary to an active gene or its mRNA transcript, to interfere with the expression of said gene. 

  • An overwhelming blow. 

verb
  • To employ the knockdown technique 

adj
  • To be formed into a head by upsetting in fastening. 

  • reduced in price, originally to a price below which an article would not be sold by the auctioneer 

  • powerful enough to overwhelm or knock down 

  • Capable of being taken apart for packing or removal. 

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