English▸ noun heavy twilled cotton cloth, especially denim:
[as modifier] a jean jacket.
– ORIGIN late 15th century (as an adjective): from Old French Janne (now Gênes), from medieval Latin Janua ‘Genoa’, the place of original production. The noun sense comes from jean fustian, literally ‘fustian from Genoa’, used in the 16th century to denote a heavy twilled cotton cloth.