'archidiaconal' originates from Late Latin, specifically the word 'archidiaconalis', where 'archi-' meant 'chief' and 'diacon-' (from Greek 'diakonos') meant 'servant' or 'deacon'.

'archidiaconal' changed from Medieval Latin 'archidiaconalis' (and via ecclesiastical Latin formations) into English in the formation of church-administrative adjectives, eventually becoming the modern English 'archidiaconal'.

Initially, it conveyed the sense 'chief servant' (from the Greek roots) but over time it evolved into the specialized ecclesiastical adjective meaning 'relating to an archdeacon' or 'relating to an archdeaconry'.