Manichaeism

The story

1. Classical Syriac · derived fromܡܐܢܝ ܚܝܐ“Living Mani”
2. Koine Greek · derived fromΜανιχαϊσμός
3. Latin · borrowed fromManichaismus
4. English todayManichaeism

From Latin Manichaismus, from Koine Greek Μανιχαϊσμός (Manikhaïsmós), from Μανιχαῖος (Manikhaîos, “Manichaeus”) [from Classical Syriac ܡܐܢܝ ܚܝܐ (Mānī ḥayyā, “Living Mani”), from ܡܐܢܝ (Mānī, “Mani”, the name of its founder) + ܚܝܐ (ḥayyā, “living, alive”)] + -ισμός (-ismós). By surface analysis, Manichaeus + -ism. Although Manichaeism is the most widespread spelling in English, it is a hypercorrection. The expected derivation from Koine Greek Μανιχαϊσμός (Manikhaïsmós) and Latin Manichaismus is Manichaism (compare with Judaism, from Ancient Greek Ἰουδαϊσμός (Ioudaïsmós), or with archaism, from Ancient Greek ἀρχαϊσμός (arkhaïsmós)).