Cumberland

"of or pertaining to the Welsh" and their kindred, the Cornish and Bretons, by 1833, from Welsh Cymru "Wales," Cymry "the Welsh," plural of Cymro, probably from ancient combrox "compatriot," from British Celtic *kom-brogos, from collective prefix *kom- (see com-) + *brogos "district," from PIE root *merg- "boundary, border." Compare Allobroges, name of a warlike people in Gallia Narbonensis, literally "those from another land." As from 1833 as a noun, "the language of the Cymry."

1747, "of or pertaining to the early medieval principality or kingdom of Cumbria or Strathclyde, from the Latin name of Cumberland. By 1780 in a modern sense "belonging to the Lake District." Cumbric as "the extinct Celtic language of Cumbria" is by 1950.