Where does “Mahometism” come from?

Mahometism (English) comes from English Mahomet, from Middle English Macomet, from Latin Machometus, from Jewish Aramaic مَحُمَّدْ, from Arabic مُحَمَّد, from Classical Persian جَان, from Middle Persian 𐫃𐫏𐫀𐫗, from Proto-Iranian *wyaHnáH — to breathe.

Ancestry of “Mahometism”, step by step

Mahometism traces back through 3 separate lines of ancestry.

via English Mahomet

StepLanguageWordMeaning
1EnglishMahometthe prophet who introduced Islam
2Middle EnglishMacometMuhammad
3LatinMachometus
4Jewish Aramaicمَحُمَّدْ
5Arabicمُحَمَّدpraised, commendable, laudable; Muhammad
6Classical Persianجَان
7Middle Persian𐫃𐫏𐫀𐫗
8Proto-Iranian*wyaHnáH
9Proto-Indo-IranianwyaHnás
10Proto-Indo-Europeanh₂enh₁‑to breathe

via French mahométisme

StepLanguageWordMeaning
1FrenchmahométismeMohammedanism
2French-ïsme-ism, variant of -isme following vowels
3Latin-ismaAlternative form of -ismus; -ism
4Latin-ismus-ism
5Ancient Greek-ισμόςForms abstract nouns
6Ancient Greek-μόςForms abstract nouns
7Proto-Indo-European-mósCreates action/result nouns from verb stems

via English ism

StepLanguageWordMeaning
1EnglishismAn ideology, system of thought, or practice that...
2English-ismUsed to form nouns of action or process or result...
Every word from Proto-Indo-European h₂enh₁‑Every word from Proto-Indo-Iranian wyaHnásEvery word from Proto-Iranian *wyaHnáH
Mahometism — Etymology, Origin & Word History | Etymology Explorer