cash vs duty

cash

adj
  • Great; excellent; cool. 

noun
  • Any of several low-denomination coins of India, China, or Vietnam, especially the Chinese copper coin. 

  • Money in the form of notes/bills and coins, as opposed to cheques/checks or electronic transactions. 

  • Cash register, or the counter in a business where the cash register is located. 

  • An instance of winning a cash prize. 

  • Liquid assets, money that can be traded quickly, as distinct from assets that are invested and cannot be easily exchanged. 

  • Money. 

verb
  • To obtain a payout from a tournament. 

  • To exchange (a check/cheque) for money in the form of notes/bills. 

  • To disband. To do away with, kill 

duty

noun
  • That which one is morally or legally obligated to do. 

  • The state of being at work and responsible for or doing a particular task. 

  • A tax placed on imports or exports; a tariff. 

  • The efficiency of an engine, especially a steam pumping engine, as measured by work done by a certain quantity of fuel; usually, the number of pounds of water lifted one foot by one bushel of coal (94 lbs. old standard), or by 1 cwt. (112 lbs., England, or 100 lbs., United States). 

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