What is "artabri"

According to Strabo, the Artabri (or Arrotrebae) were an ancient Gallaecian Celtic tribe, living in the extreme north-west of modern Galicia, about Cape Nerium (Finisterre), in the later counties of A Coruña or Ferrol. Strabo reports several seaports among the Artabri. Ptolemy places them among Galaeci Lucenses and gives their capital town as Lucus Augusti (now Lugo).