drawback vs knock-on

drawback

noun
  • A disadvantage; something that detracts or takes away. 

  • The inhalation of a lungful of smoke from a cigarette. 

  • A partial refund of an import fee, as when goods are re-exported from the country that collected the fee. 

knock-on

noun
  • Resulting as an indirect effect. 

  • A foul in which a player knocks the ball forward. 

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