Where does “monarthritic” come from?

monarthritic (English) comes from English Mon, from English monster, from Middle English monstre, from Old French monstre, from Latin mōnstrum, from Proto-Italic monestrom.

Ancestry of “monarthritic”, step by step

monarthritic traces back through two separate lines of ancestry.

via English Mon

StepLanguageWordMeaning
1EnglishMonAbbreviation of Monday; A member of a people...
2EnglishmonsterA terrifying and dangerous creature; A bizarre or...
3Middle EnglishmonstreA monster or beast; a horrific or frightening...
4Old Frenchmonstremonster
5Latinmōnstruma divine omen indicating misfortune, an evil omen, portent
6Proto-Italicmonestrom

via English arthritic

StepLanguageWordMeaning
1EnglisharthriticOf, or affected by arthritis; A person with...
2Latinarthriticusgouty, arthritic
3Ancient Greekαρθριτικός
Every word from Proto-Italic monestromEvery word from Latin mōnstrumEvery word from Old French monstre