'antonomastical' originates from Greek, specifically the word 'antonomasia', where 'anti-' meant 'in place of' (or 'instead of') and 'onoma' meant 'name'.

'antonomastical' developed from Late Latin and Medieval Latin 'antonomasia' (from Greek), passed into English as the noun 'antonomasia', and later produced adjective forms such as 'antonomastic' and 'antonomastical'.

Initially it referred specifically to 'the act or device of replacing a name' (antonomasia); over time adjectival forms came to mean 'relating to or characteristic of that device' and are used to describe expressions that employ this naming substitution.