a person who holds religious beliefs that are not part of any of the world’s main religions 异教徒（信奉非主流宗教者） - (often disapproving)
used in the past by Christians to describe a person who did not believe in Christianity 教外人（旧时的基督徒用以指非基督徒）
Word Originlate Middle English: from Latin paganus ‘villager, rustic’, from pagus ‘country district’. Latin paganus also meant ‘civilian’, becoming, in Christian Latin, ‘heathen’ (i.e. one not enrolled in the army of Christ).