ARRABO(Ἀραβών, Ptol. 2.11.5, 2.16. § § 1, 2).
1. A river, one of the feeders of the Danube, and the boundary between Upper and Lower Pannonia. It entered the Danube just below the modern royal borough of Raab.
2. ARRABONE(in the ablative case, Georg. Ravenna, 4.19), or ARRABONA,in its later form, was a city of Pannonia situated near the junction of the river Arrabo with the Danube. It was a place of some importance under the lower empire, and was garrisoned by detachments of the tenth and fourteenth legions. It is probably the ARBON(Ἄρβων) of Polybius (Plb. 2.11). The royal borough of Raabcorresponds nearly with the ancient Arrabo. ( It. Anton. p. 246; Tab. Peutinger.; Notitia Imperii. ) [W.B.D]