down payment vs repayment

down payment

noun
  • A payment representing a fraction of the price of something being purchased, made to secure the right to continue making payments towards that purchase. 

  • Any initial commitment signifying an intention to carry out a larger future commitment, even though no legal rights or obligations are secured. 

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 down payment and repayment occurred in a corpus of books? (source: Google Ngram Viewer )