'adnoun' originates from Latin, specifically the word 'adnomen', where 'ad-' meant 'to' and 'nomen' meant 'name'.

'adnomen' transformed into the English word 'adnoun' and eventually became the modern English word 'adnoun'.

Initially, it meant 'a name added to another', but over time it evolved into its current meaning of 'a word that functions as an adjective'.