'antonomasy' originates from Greek, specifically the word 'antonomasia', where 'anti-' meant 'instead of' and 'onoma' meant 'name'.

'antonomasy' changed from the Greek word 'antonomasia' into Late Latin and Medieval Latin use, entered English via Latin/French rhetorical and scholarly usage, and became the modern English 'antonomasy'.

Initially, it meant 'the act of renaming' or 'a change of name', but over time it evolved into the specific rhetorical meaning of substituting a descriptive phrase for a name or using a name to signify a type.