'archiprelatical' originates from the Greek prefix 'archi-' meaning 'chief' combined with Latin 'praelatus' (from which 'prelate' derives), where 'praelatus' meant 'preferred' or 'placed before' in an ecclesiastical sense.

'archiprelatical' developed via Medieval Latin formations such as 'archipraelatus' (a compound of Greek 'archi-' + Latin 'praelatus'), passed into later ecclesiastical Latin and English usage as 'archiprelate' or related adjectival forms, and eventually yielded the English adjective 'archiprelatical'.

Initially the components referred to a 'chief' + 'preferred/placed before' (i.e., a principal prelate or chief ecclesiastical officer); over time the compound came to be used adjectivally to mean 'pertaining to such a chief prelate', which is its current sense.