I.the avenging deity, destroying angel, Trag.; ἀλ. οὑμός Soph.; βουκόλων ἀλάστωρ the herdsmen's plague, of the Nemean lion, id=Soph.
II.pass. he who suffers from such vengeance, an accursed wretch, Aesch., Dem.
Either from ἄλαστος, or from ἀλάομαι, he that makes to wander.