entwerten

Entwerten is a German verb that means to cancel the validity or value of something, usually by marking or otherwise rendering it unusable. The term is used in various contexts to indicate that an object or right has lost its intended function or worth. The related noun is Entwertung.

In philately, entwertung refers to the cancellation of postage stamps to prevent their reuse. Cancellations can be performed with ink stamps, perforations, or electronic devices, and the resulting mark shows that the stamp has already been spent.

In transportation and ticketing, entwerten describes the process of validating a ticket or smart card to confirm that it can be used for travel. Validation typically occurs at ticket machines, turnstiles, or validation devices, and it marks the ticket as consumed for a specific journey or time period.

Economically, entwertung is used to describe the devaluation of money or currency, where a currency loses value relative to others or its purchasing power within an economy. This sense is often referred to as Entwertung or Geldentwertung and can result from inflation, monetary policy, or structural reforms.

In administrative and legal contexts, documents, licenses, or credentials can be entwertet to render them invalid, for instance after expiration, loss, or replacement. An entwertetes document cannot be used for its original purpose, and a new or renewed version typically replaces it.