(Ἑταιρεῖος), the protector of companies or associations of friends, a surname of Zeus, to whom Jason was believed to have offered the first sacrifices, when the Argonauts were assembled for their expedition. (Athen. 13.572.)
[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