'authorially' originates from English, specifically from the adjective 'authorial', which itself derives from the noun 'author'. The noun 'author' comes via Old French 'auctor' from Latin 'auctor', where 'auctor' meant 'originator' or 'promoter'.

'authorially' formed from the adjective 'authorial' + the adverbial suffix '-ly'. 'Authorial' was created from 'author' (Middle English 'author', from Old French 'auctor', from Latin 'auctor'). Over time the adjective took the suffix '-ial' to mean 'relating to an author', and adding '-ly' produced the adverb 'authorially'.

Initially, the Latin root 'auctor' meant 'originator' or 'one who causes', and through Old French and Middle English the sense shifted to 'one who writes' (author). From this developed 'authorial' meaning 'relating to the author', and 'authorially' now means 'in a manner characteristic of an author'.