debt vs fee

debt

noun
  • Money that one person or entity owes or is required to pay to another, generally as a result of a loan or other financial transaction. 

  • An action, state of mind, or object one has an obligation to perform for another, adopt toward another, or give to another. 

  • The state or condition of owing something to another. 

  • An action at law to recover a certain specified sum of money alleged to be due 

fee

noun
  • An additional monetary payment charged for a service or good that is minor compared to the underlying cost. 

  • A right to the use of a superior's land as a stipend for certain services to be performed, typically military service. 

  • Synonym of fief: the land so held. 

  • An inheritable estate in land, whether absolute and without limitation to potential heirs (fee simple) or with limitations to particular kinds of heirs (fee tail). 

  • An inheritable estate in land held of a feudal lord on condition of performance of certain services, typically military service. 

verb
  • To reward for services performed, or to be performed; to recompense; to hire or keep in hire; hence, to bribe. 

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