resident (as in name used to describe the resident or native of a particular place) n. demonym

There is a floating island of trash in the North Pacific as big as the country of France. … Environmental activists have banded together and petitioned the United Nations to recognize the island as an actual country [called] the Trash Isles. .   Trash Islanders [would be] the demonym for citizens of the Trash Isles. (Erik Deckers, “Can a Floating Island of Trash Become a Country?.” The Times-Post (Pendleton, Indiana), 9/28/2017.)

demonym can also be a synonym for the name used to describe the dweller, occupant, or native of a particular place.