A genericized trademark (also known as a generic trade mark or proprietary eponym) is a trademark or brand name that has become the colloquial or generic description for (or synonymous with) a particular class of product or service.

A trademark typically becomes "genericized" when the products or services with which it is associated have acquired substantial market dominance or mind share. The term is legally significant in that unless a company works sufficiently to prevent such broad use of its trademark, its intellectual property rights in the trademark may be lost.