'autonomasy' originates from Greek elements, specifically 'autó' and 'ónoma', where 'autó-' meant 'self' and 'ónoma' meant 'name'.

'autonomasy' developed as an English formation modeled on classical Greek compounds and related rhetorical terms (such as 'antonomasia'), passing through Medieval/Modern Latin scholarly usage into English as a specialized rhetorical term.

Initially formed with the sense of 'self-name' from its Greek roots, it came to denote the rhetorical practice of substituting names or using names generically; this rhetorical sense is the modern usage.