Jeans cloth was named after a city.
The history of jeans goes as far back as the 16th century when sailors in Genoa (Italy) wore a material that eventually became the material used in jeans. The word ‘jean’ derives from the name of the Italian port city Genoa, as it was a custom to name a material after its place of origin. By the late 16th century, jean material was already produced in Lancashire, England.