Euius

(Εὔιος). A surname of Bacchus, given him, according to the poets, by Zeus, whom he was aiding in the contest with the giants. Zeus was so delighted with his valour that he called out to him, Εὖ υἷε, “Well done, O son!” Others suppose it to have originated from a cry of the Bacchantes, Εὐοῖ. Cf. Lachm. on Lucret. v. 743.