deonym

From de- +‎ -onym (“name”). Compare Italian deonomastica (“words of a language that are derived from given names, last names, ethnonyms, and toponyms”), from de- +‎ onomastica.

deonym (plural deonyms)

1. A term which derives from a proper name (a proper noun), such as a brand name, a given name, a surname or a place name.
   • 2013 August 19, Oliviu Felecan, Onomastics in Contemporary Public Space, Cambridge Scholars Publishing, →ISBN, page 172:

     [...] increased occurrence of deonyms. Among them, nearly half come from trade names (company names, brand names or product names). This chapter aims to study deonyms deriving from trade names. An attempt will be made to understand why these proper names have […]

   • 2021 October 25, Doris Berger-Grabner, Strategic Retail Management and Brand Management: Trends, Tactics, and Examples, Walter de Gruyter GmbH & Co KG, →ISBN, page 318:

     In linguistics, such terms that have managed the transformation from a proper brand name to a generic name are called deonyms […] The field of deonyms is not limited to brand names: The verb “röntgen,” for example, is derived from the discoverer of the rays named after him and is also a deonym. Some […]

   • 2025 March 31, Joachim Grzega, The Routledge Handbook of Eurolinguistics, Taylor & Francis, →ISBN:

     A third name for common words from proper nouns is the lexical type deonyms (with the study of deonyms referred to as deonomastics) (cf., e.g., La Stella 1984). For this chapter, eponym shall be defined as 'word going back to a proper noun (e.g. anthroponym, toponym, ethnonym)'. The chapter will focus on highly lexicalized words […]

From Latin deus (“god”) +‎ -onym.

deonym (plural deonyms)

1. Synonym of theonym.
   • 1963, Congrès international d'études gauloises, celtiques et protoceltiques, Actes:

     A similar phenomenon occurs often, and also in connection with old Celtic toponyms which, if deonyms, were often suppressed by the growing might of the Church, […] [these other] deonyms serve to prove the Pelasgians spoke an Indo-European language far […]

     (please add an English translation of this quotation)

   • 1979, The Journal of Indo-European Studies:

     It is a known fact that many Greek deonyms are not based [on] Hellenic roots (just as the oldest Sumerian place and river [name]s are neither Sumerian nor Semitic […]

   • 2012 December 6, C. Musés, Destiny and Control in Human Systems: Studies in the Interactive Connectedness of Time (Chronotopology), Springer Science & Business Media, →ISBN, page 124:

     The Anglo-Saxon root Tues is related to the Teutonic deonym Tiwas, in turn related to the Latin Deus, the Baltic Dievas, and the Sanskrit Deva.