An eponym is a noun that refers to a person, place, or thing after which something else is named. It can also refer to the name itself that is derived from that person or thing. For example, the state of Pennsylvania is an eponym derived from William Penn, and Alzheimer's disease is named after the neurologist Alois Alzheimer. The word "eponymous" is the adjective form used to describe someone or something that gives their name to something else, such as an eponymous character in a book or an eponymous company named after its founder.
