An eponym is a person, a place, or thing for whom or for which something is named, or believed to be named. For example, Elizabeth I of England is the eponym of the Elizabethan era.

Many genericized trademarks such as aspirin,heroin and thermos are based on their original brand eponyms.

The adjectives derived from eponym, which include eponymous and eponymic, similarly refers to being the person or thing after whom something is named, as "the eponymous founder of the Ford Motor Company" refers to founder's being Henry Ford. Recent usage, especially in the recorded-music industry, also allows eponymous to mean "named after its central character or creator".

History

Time periods have often been named after a ruler or other influential figure: