'antiprelatic' originates from the prefix 'anti-' (from Greek 'anti-' meaning 'against') combined with 'prelatic', ultimately from Latin 'praelatus'/'praelaticus' (relating to a prelate).

'antiprelatic' developed in English by combining 'anti-' with earlier English/Latin forms such as 'antiprelatical' (17th century usage); 'prelate' itself came into Middle English via Old French 'prelat' from Latin 'praelatus' and the adjective form from Medieval/Latin 'praelaticus'.

Initially it meant 'against prelacy or prelates' and over time has retained that core sense of opposition to episcopal/prelatical authority.