General English


  • noun a legal document in which the producer agrees to compensate the buyer if the product is faulty or becomes faulty before a specific date after purchase
  • noun something given as a security


  • A legally enforceable assurance of quality or performance of a product or work, or of the duration of satisfactory performance. See also guaranty, warranty.

Information & Library Science

  • noun a written promise that any faults in a purchase which show within a given period of time will be repaired free of charge


  • noun a promise made by someone that they will do something such as pay another person’s debts if the other person fails to do it.


  • noun a legal document which promises that a machine will work properly, that an item is of good quality or that a service will be provided

Origin & History of “guarantee”

Guarantee is essentially the same word as warrant, which is of Germanic origin (Germanic initial w- became g(u)- in the romance languages). It was probably borrowed into English from the Spanish form garante (this is suggested by early spellings garanté and garante in English), and later changed to guarantee through confusion with guaranty (16th c.) (itself originally a variant of warranty).