or Hadria, (anc. geogr.) the name of two towns in Italy. One in the country of the Veneti, on the river Tartarus, between the Padus and the Athetis, called Atria by Pliny and Ptolemy, but Adria by Strabo. Another on the river Vomanus, in the territory of the Piceni, (to which Antonine's Itinerary from Rome is directed,) the country of the ancestors of the emperor Adrian. From which of these the Adriatic sea is denominated, is matter of doubt. A third opinion is, that it is so called from Adrian the son of Joan, of Italian origin; (Eutalius in Dionysium.)

ADRIANUM (or Adriaticum) Mare, (anc. geogr.) now the Gulf of Venice, a large bay in the Mediterranean, between Dalmatia, Slavonia, Greece, and Italy. It is called by the Greeks, Αδριανός Κόλπος; and Adria by the Romans, as Arbiter Adria Notur. Hor. Cicero calls it Hadriannum Mare; Virgil has Hadriaeas Undas. It is commonly called Mare Adriaticum, without an aspiration; but whether it ought to have one, is a dispute: if the appellation is from Hadria, the town of the Piceni, it must be written Hadriaticum, because the emperor's name, who thence derives his origin, is on coins and stones Hadrianus; but if from the town in the territory of Venice, as the more ancient, and of which that of the Piceni is a colony, this will justify the common appellation Adriaticum.