Sir George Downing built Downing Street but never lived there
Naming things after people is ancient: Assyrians labelled each year after an official in the second millennium BC. Eponyms now run from the sandwich to Parkinson disease, and they are shifting. Medical writers are dropping the possessive apostrophe, and North American ornithologists decided in 2024 to rename every bird called after a person.
An eponym is the person or thing something is named after, and the word also works the other way round: Elizabeth I is the eponym of the Elizabethan era, and the era can be called hers. John Montagu, 4th Earl of Sandwich, lent his title to a snack. Downing Street honours Sir George Downing, who built its houses as an investment and never moved in. Verbs can be eponyms too, as with bowdlerize.
Dating by names was once routine. Athens called each year after its chief magistrate, so 594 BC belonged to Solon. Rome cited the two consuls; 59 BC was jokingly dubbed the consulship of Julius and Caesar because his colleague counted for so little. Ptolemaic Egypt used a priest of the royal cult. Regnal years survived in British statute citation, with England abandoning the practice only in 1963. Genesis explains whole peoples through a founding ancestor, such as the Edomites and Moabites, and Greek tribes such as the Dorians claimed a legendary Dorus.
Science is full of them, from the Avogadro constant to the element meitnerium and the Apgar score, though Stigler's law warns that discoveries are rarely named after whoever actually made them. A global study of 2,416 bird eponyms, about 21% of all species, found most honour people from countries where the bird does not live, frequently scientists, aristocrats and officers of colonial empires, with namings peaking during colonial expansion. Such concerns led the American Ornithological Society to its sweeping 2024 decision to replace person-based common names across North America.
Style rules add a final twist. As a term becomes generic, it tends to lose its capital: quixotic and diesel are often lowercase, and herculean may be when used figuratively. Medical dictionaries have moved toward non-possessive forms over recent decades, favouring Parkinson disease over Parkinson's disease. One neuropathology paper argues the same for Alzheimer disease, noting that searching PubMed for the two spellings returns only partly overlapping results, a real problem for systematic reviews. Music provides the tangles: Black Sabbath's song Black Sabbath, named after a 1963 film, gave the band its name and title track.
Source: Eponym
