(n.) Erroneous or false belief.

Albigensianism Arianism Catharism Ebionitism Erastianism Gnosticism Jovinianism Lollardy Manichaeanism Manichaeism Monophysism Monophysitism Pelagianism Waldensianism Wyclifism airy nothing antinomianism autism bubble chimera daydream deception deluded belief delusion dereism dream dream vision dreamland dreamworld emanatism error fallacy false belief false doctrine heresy hylotheism ignis fatuus illusion misconception pantheism pipe dream self-deceit self-deception self-delusion trick trip vapor wrong impression