Proprietary eponym

A generic trademark, also known as a genericized trademark or proprietary eponym, is a trademark or brand name that, due to its popularity and/or significance, has become the generic name for, or synonymous with, a general class of product or service, usually against the intentions of the trademark's holder.

A trademark is said to become genericized when it begins as a distinctive product identifier but changes in meaning to become generic. This typically happens when the products or services with which the trademark is associated have acquired substantial market dominance or mind share, such that the primary meaning of the genericized trademark becomes the product or service itself rather than an indication of source for the product or service. A trademark thus popularized has its legal protection at risk in some countries such as the United States and United Kingdom, as its intellectual property rights in the trademark may be lost and competitors enabled to use the genericized trademark to describe their similar products, unless the owner of an affected trademark works sufficiently to correct and prevent such broad use.

Thermos,Kleenex, Dumpster and Realtor are examples of trademarks that have become genericized in the US.

Genericization or "loss of secondary meaning" may be either among the general population or among just a subpopulation, for example, people who work in a particular industry. Some examples of the latter type from the vocabulary of physicians include the names Luer-Lok (Luer lock), Phoroptor (phoropter), and Port-a-Cath (portacath), which have genericized mind share (among physicians) because (1) the users may not realize that the term is a brand name rather than a medical eponym or generic-etymology term, and (2) no alternative generic name for the idea readily comes to mind. Most often, genericization occurs because of heavy advertising that fails to provide an alternative generic name or that uses the trademark in similar fashion to generic terms. Thus, when the Otis Elevator Company advertised that it offered "the latest in elevator and escalator design," it was using the well-known generic term "elevator" and Otis's trademark "Escalator" for moving staircases in the same way. The Trademark Office and the courts concluded that, if Otis used their trademark in that generic way, they could not stop Westinghouse from calling its moving staircases "escalators", and a valuable trademark was lost through genericization.

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