Lewis & Short

Ārădĭus, a, um, adj., of or belonging to Aradus (now Ruad), a city on an island of the same name on the coast of Phœnicia (Plin. 5, 20, 17, § 78; Mel. 2, 7; cf. Mann. Phoenic. p. 309): quod genus endo marist Aradī fons, Lucr. 6, 891.
Hence, Ārădĭi, ōrum, m., the inhabitants of Aradus, Plin. 5, 20, 17, § 78.