letting vs rental

letting

noun
  • Synonym of tenancy. 

  • Hyponyms: sublease, underlease, subtenancy, undertenancy, subletting, underletting, (informal) sublet, underlet 

rental

noun
  • An act of renting. 

  • A business that rents out something to its customers. 

  • The payment made to rent something. 

  • Something that is rented. 

  • A player traded to a team with a year or less on his contract 

adj
  • Relating to renting. 

  • Relating to rent. 

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