'authoring' ultimately originates from Latin, specifically the word 'auctor', where the root 'auc-/auct-' (from 'augere') meant 'to increase' or 'to originate'.

'auctor' in Latin passed into Old French as 'autor/auteur' and into Middle English as 'author'; the modern verb 'author' and its gerund 'authoring' developed from these forms.

Initially it referred to an 'originator' or 'promoter' (one who causes or increases); over time the sense narrowed to 'writer' and to the modern sense of producing written works or creating content—hence 'authoring' as the act of writing or creating.