kickback vs repayment

kickback

noun
  • A covert, often illegal, payment in return for a favor consisting of providing an opportunity of chargeable transaction; a kind of bribe. 

  • A backward kick, a retrograde movement of an extremity. 

  • recoil; a sudden backward motion, usually in the direction of the operator. 

  • An accident wherein the upper tip of the bar of a running chainsaw contacts a relatively immovable object, forcing the bar upwards and pressing the running chain more firmly against the object, causing the saw to be hurled upwards and backwards into the operator's face. 

  • A dangerous buildup of gas pressure at the wellhead. 

  • In contract bridge, an ace asking convention initiated by the first step above four of the agreed trump suit. 

  • An accident where an object being cut by a rotating blade or disk, such as a circular saw, is caught by the blade and thrown outward. 

  • The board separating one bowling lane from another at the pit end. 

  • A feature that saves the ball from draining and propels it back into play. 

  • A relaxed party. 

repayment

noun
  • The money or other item that is repaid. 

  • The act of revenge, an act of revenge. 

  • The act of repaying. 

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