buy vs exchange

buy

noun
  • Something which is bought; a purchase. 

verb
  • To make a purchase or purchases, to treat (for a drink, meal or gift) 

  • To make a bluff, usually a large one. 

  • To bribe. 

  • To be equivalent to in value. 

  • To obtain (something) in exchange for money or goods. 

  • To obtain, especially by some sacrifice. 

  • to accept as true; to believe 

exchange

noun
  • An act of exchanging or trading. 

  • The transfer of substances or elements like gas, amino-acids, ions etc. sometimes through a surface like a membrane. 

  • The fourth through sixth digits of a ten-digit phone number (the first three before the introduction of area codes). 

  • The loss of a minor piece (typically a bishop or knight) and associated capture of the more advantageous rook. 

  • A telephone exchange. 

  • A conversation. 

  • The difference between the values of money in different places. 

  • A place for conducting trading. 

  • The loss of one piece and associated capture of another. 

verb
  • To trade or barter. 

  • To replace with, as a substitute. 

  • To recommend and get recommendations. 

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