Lewis & Short

Drancae or Drangae, ārum, m., a Persian or Bactrian tribe, Plin. 6, 23, 25, § 94; Curt. 6, 6, 18; 8, 3, 9.
Hence, Dran-caeus or Drangaeus, a, um, adj., of the Drancae, Val. Fl. 6, 106; 507.