crétin

Probably a doublet of chrétien (“Christian”), from Latin Christianus (from an Alpine French dialect crestin, undergoing some Franco-Provençal-like sound changes). Specifically, likely from a dialect in the Swiss/Alpine francophone region where there was once an endemic level of cretinism. It is also linked, somewhat euphemistically, to one of the older senses of the word, referring to any Christian man, peasant, simple or regular person, and in some cases by extension a "poor/unfortunate fellow"