Umbri

Borrowed from Latin umbrī. Also called Ombrii in some Roman sources. Many Roman writers thought the Umbri to be Celtic; Cornelius Bocchus wrote that they descended from an ancient Gaulish tribe. Plutarch wrote that the name might be a different way of writing the name of the Celtic tribe Ambrones, which loosely means "King of the Boii". He also suggested that the Insubres, another Gaulish tribe, might be connected; their Celtic name Isombres could possibly mean "Lower Umbrians", or inhabitants of the country below Umbria.

来源：wiktionary