Yours, Etc.: Origins and Uses of 8 Sign-Offs
"twilled cotton cloth," mid-15c., from Middle French jean fustian "fustian (a type of twilled cotton cloth) of Genoa," the city in Italy, from Old French Jannes "Genoa," from Latin Genua (see Genoa). The plural form jeans became standard 19c.
A dialect of JOSS.