(Ἁλιθέρσης), a son of Mastor of Ithaca. He was a soothsayers, and during the absence of Odysseus he remained behind in Ithaca and assisted Telemachus against the suitors of Penelope. (Hom. Od 2.157, 253, 24.451.) Another mythical personage of this name is mentioned by Pausanias. (7.4.1.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890