'antipapal' is formed from the prefix 'anti-' (from Greek 'anti-' meaning 'against') combined with 'papal' (from Latin 'papalis', relating to 'papa' meaning 'pope' or 'father').

'papal' comes from Latin 'papalis', ultimately from Greek 'pappas'/'pappas' (meaning 'father' or 'bishop'), and English combined the prefix 'anti-' with 'papal' to create 'antipapal'.

Initially formed to mean 'against the pope or papal authority', the term has retained this basic meaning in modern usage.