The mythological Greek hero Orion is the eponym of the constellation Orion, shown here, and thus indirectly of the Orion spacecraft.[1]

An eponym is a person, a place, or a thing after whom or which someone or something is, or is believed to be, named. The adjectives which are derived from the word eponym include eponymous and eponymic.

Usage of the word

The term eponym[2][3] functions in multiple related ways, all based on an explicit relationship between two named things. A person, place, or thing named after a particular person share an eponymous relationship. In this way, Elizabeth I of England is the eponym of the Elizabethan era, but the Elizabethan era can also be referred to as the eponym of Elizabeth I of England.

When Henry Ford is referred to as "the eponymous founder of the Ford Motor Company", his surname "Ford" and the name of the motor company have an eponymous relationship. The word "eponym" can also refer to the title character of a fictional work (such as Rocky Balboa of the Rocky film series), as well as to self-titled works named after their creators (such as the album The Doors by the band the Doors).

Walt Disney created the eponymous Walt Disney Company, with his name similarly extended to theme parks such as Walt Disney World.[4][5][6][7] Medical eponymous terms are often called medical eponyms although that usage is deprecable.


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


Other eponyms

Orthographic conventions

Capitalized versus lowercase

For examples, see the comparison table below.

Genitive versus attributive

National varieties of English

Comparison table of eponym orthographic styling

Prevalent dictionary styling today Stylings that defy prevalent dictionary styling Comments
Addison disease[28] *Addison Disease
*addison disease
Allemann syndrome[28] *Allemann Syndrome
*allemann syndrome
cesarean [only][28]
cesarean also cesarian [but no cap variant][16]
cesarean, "often capitalized" or caesarean also cesarian or caesarian[29]
  More information on this word's orthographic variants is at Wiktionary: caesarean section.
darwinian [only][28]
darwinism [only][28]
Darwinian [only][16][17]
Darwinism [only][16][17]
Darwinist [only][16][17]
diesel (n/adj/vi) [no cap variant][16][17]
and also
diesel engine[16][17]
dieselize, dieselization[16]
*Diesel engine
*Dieselize, Dieselization
draconian often Draconian[16]
eustachian [only][28]
eustachian often Eustachian[16]
eustachian tube [only][28]
eustachian tube often Eustachian tube[16]
eustachian tube or Eustachian tube[17]
*Eustachian Tube  
fallopian [only][28]
fallopian often Fallopian[16]
fallopian tube [only][28]
fallopian tube often Fallopian tube[16]
fallopian tube also Fallopian tube[17]
*Fallopian Tube  
Marxism [only][16][17]
Marxist [only][16][17]
mendelian [only][28] or Mendelian [only][16]
mendelian inheritance [only][28] or Mendelian inheritance [only][16] 
Mendel's laws[16][28]
*Mendelian Inheritance  
Newtonian [only][16][17] *newtonian  
parkinsonism [only][16][28]
parkinsonian [only][16][28]
parkinsonian tremor[28]
Parkinson disease [only][28]
Parkinson's disease [only][16]
*Parkinsonian tremor
*Parkinsonian Tremor
*Parkinson Disease
*Parkinson's Disease
quixotic [only][16][17] *Quixotic  
Roman numerals[17]
roman numerals[16]
  AMA Manual of Style lowercases the terms roman numerals and arabic numerals. MWCD enters the numeral sense under the headword Roman but with the note "not cap" on the numeral sense.[16]

Lists of eponyms

By person's name

By category

See also


  1. ^ "Orion Spacecraft - Nasa Orion Spacecraft". 15 July 2016. Archived from the original on 6 August 2016. Retrieved 2 February 2013.
  2. ^ (ancient Greek ἐπώνυμος (a.) given as a name, (b.) giving one's name to a thing or person, ἐπί upon + ὄνομα, Aeolic ὄνυμα name)
  3. ^ "eponym, n. : Oxford English Dictionary". OED Online. 2019-10-26. Archived from the original on 2019-10-26. Retrieved 2019-10-27.
  4. ^ "eponym". LLC. Archived from the original on 4 March 2016. Retrieved 30 December 2014.
  5. ^ "eponym". Merriam-Webster Online Dictionary. Merriam-Webster. Archived from the original on 21 April 2016. Retrieved 30 December 2014.
  6. ^ "eponymous". LLC. Archived from the original on 4 March 2016. Retrieved 30 December 2014.
  7. ^ "eponymous". Merriam-Webster Online Dictionary. Merriam-Webster. Archived from the original on 21 May 2016. Retrieved 30 December 2014.
  8. ^ Bayer Co. v. United Drug Co., 272 F. 505 (S.D.N.Y. 1921) Archived 2011-09-08 at the Wayback Machine, Berkman Center for Internet & Society at Harvard University, accessed March 25th, 2011
  9. ^ Harper, Douglas. "heroin". Online Etymology Dictionary.
  10. ^ King-Seeley Thermos Co. v. Aladdin Indus., Inc., 321 F.2d 577 (2d Cir. 1963); see also this PDF Archived 2006-02-09 at the Wayback Machine
  11. ^ Beolens, Bo; Watkins, Michael; Grayson, Michael (2014). The Eponym Dictionary of Birds. Bloomsbury Publishing. ISBN 978-1472905741.
  12. ^ Hämäläinen, Matti (2015). "Catalogue of individuals commemorated in the scientific names of extant dragonflies, including lists of all available eponymous species-group and genus-group names" (PDF). International Dragonfly Fund (IDF) - Report. 80: 1–168. ISSN 1435-3393. Archived (PDF) from the original on 19 July 2021. Retrieved 18 September 2020.
  13. ^ Lauer, Tod. "Astronomical Eponyms". National Optical Astronomy Observatory. Archived from the original on 2021-08-22. Retrieved 2021-08-22.
  14. ^ a b c Waddingham, Anne (28 August 2014). New Hart's Rules: The Oxford Style Guide. OUP Oxford. p. 105. ISBN 978-0199570027.
  15. ^ Marthus-Adden Zimboiant (2013-08-05). No Grammar Tears 1. pp. 256–257. ISBN 9781491800751.
  16. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac Merriam-Webster (1993), Merriam-Webster's Collegiate Dictionary (10th ed.), Springfield, Massachusetts, US: Merriam-Webster, ISBN 978-0-87779-707-4
  17. ^ a b c d e f g h i j k l m n o Houghton Mifflin (2000), The American Heritage Dictionary of the English Language (4th ed.), Boston and New York: Houghton Mifflin, ISBN 978-0-395-82517-4
  18. ^ University of Chicago (1993). The Chicago Manual of Style (14th ed.). Chicago: University of Chicago Press. § 7.49, pp. 253–254. ISBN 0-226-10389-7.
  19. ^ Villemaire, Lorraine; Oberg, Doreen (29 December 2005). Grammar and Writing Skills for the Health Professional (2nd Revised ed.). Delmar Cengage Learning. p. 167. ISBN 978-1401873745.
  20. ^ Centers for Disease Control and Prevention. Emerging Infectious Diseases Style Guide. Preferred Usage Archived 2014-06-13 at the Wayback Machine
  21. ^ Lisa Brown; Julie M. Wolf; Rafael Prados-Rosales; Arturo Casadevall (2015). "Through the wall: extracellular vesicles in Gram-positive bacteria, mycobacteria and fungi". Nature Reviews Microbiology. 13 (10): 620–630. doi:10.1038/nrmicro3480. PMC 4860279. PMID 26324094.
  22. ^ Kristen L. Mueller (12 June 2015). "Detecting Gram-negative bacteria". Science. 348 (6240): 1218. doi:10.1126/science.348.6240.1218-o.
  23. ^ "Gram-positive". Archived from the original on 2016-10-20. Retrieved 2016-10-22.
  24. ^ "Newtonian". Merriam-Wester. Archived from the original on 2016-10-23. Retrieved 2016-10-22.
  25. ^ "New·ton". The American Heritage Dictionary. Archived from the original on 2016-10-22. Retrieved 2016-10-22.
  26. ^ Iverson, Cheryl, ed. (2007), AMA Manual of Style (10 ed.), Oxford, England: Oxford University Press, ISBN 978-0-19-517633-9, chapter 16: Eponyms.
  27. ^ Medical Subject Headings (MeSH) of the United States National Library of Medicine (NLM) uses "cesarean section" Archived 2021-03-13 at the Wayback Machine, while the also US-published Saunders Comprehensive Veterinary Dictionary uses "caesarean" Archived 2020-07-29 at the Wayback Machine. The online versions of the Merriam-Webster Dictionary Archived 2020-07-27 at the Wayback Machine and American Heritage Dictionary Archived 2020-07-29 at the Wayback Machine list "cesarean" first and other spellings as "variants", an etymologically anhistorical position.
  28. ^ a b c d e f g h i j k l m n o p Elsevier (2007), Dorland's Illustrated Medical Dictionary (31st ed.), Philadelphia: Elsevier, ISBN 978-1-4160-2364-7
  29. ^ Merriam-Webster (2003), Merriam-Webster's Collegiate Dictionary (11th ed.), Springfield, Massachusetts, US: Merriam-Webster, ISBN 978-0-87779-809-5