ALONTIUM, (anc. geogr.) a town in the north of Sicily, situated on a steep eminence, at the mouth of the Chydas, (Ptolemy, Pliny, Cicero;) said to be as old as the war of Troy, (Dionys. Halicar.) Now in ruins; from which arose the hamlet St Filadelfo, in the Val di Demona. The inhabitants were called Haluntini, (Cicero.)