Deonym

[…] 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.

Source: wiktionary

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.

Source: wiktionary

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)'.

Source: wiktionary

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[…]

Source: wiktionary