keel vs knockdown

keel

noun
  • A type of flat-bottomed boat. 

  • A broad, flat vessel used for cooling liquids; a brewer's cooling vat; a keelfat. 

  • In a dirigible, a construction similar in form and use to a ship's keel; in an aeroplane, a fin or fixed surface employed to increase stability and to hold the machine to its course. 

  • A large beam along the underside of a ship’s hull from bow to stern. 

  • The two lowest petals of the corolla of a papilionaceous flower, united and enclosing the stamens and pistil; a carina. 

  • A rigid, flat piece of material anchored to the lowest part of the hull of a ship to give it greater control and stability. 

  • Red chalk; ruddle. 

  • The rigid bottom part of something else, especially an iceberg. 

  • The periphery of a whorl extended to form a more or less flattened plate; a prominent spiral ridge. 

verb
  • To turn up the keel; to show the bottom. 

  • to collapse, to fall 

  • To traverse with a keel; to navigate. 

  • To mark with ruddle. 

knockdown

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

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

  • 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 keel and knockdown occurred in a corpus of books? (source: Google Ngram Viewer )