exchange vs keep

exchange

verb
  • To trade or barter. 

  • To replace with, as a substitute. 

  • To recommend and get recommendations. 

noun
  • 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. 

  • An act of exchanging or trading. 

  • 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. 

keep

verb
  • To have habitually in stock for sale. 

  • To supply with necessities and financially support (a person). 

  • To refrain from freely disclosing (a secret). 

  • To continue in (a course or mode of action); to not intermit or fall from; to uphold or maintain. 

  • To remain edible or otherwise usable. 

  • To remain in a state. 

  • To observe; to adhere to; to fulfill; to not swerve from or violate. 

  • To raise; to care for. 

  • To act as wicket-keeper. 

  • To enter (accounts, records, etc.) in a book. 

  • To maintain the condition of; to preserve in a certain state. 

  • To restrain. 

  • To maintain (an establishment or institution); to conduct; to manage. 

  • To watch over, look after, guard, protect. 

  • To maintain possession of. 

  • To record transactions, accounts, or events in. 

  • To remain faithful to a given promise or word. 

  • To continue. 

noun
  • The state of being kept; hence, the resulting condition; case. 

  • A cap for holding something, such as a journal box, in place. 

  • The food or money required to keep someone alive and healthy; one's support, maintenance. 

  • The main tower of a castle or fortress, located within the castle walls. 

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