Iole was the daughter of Eurytus, king of Oechalia, who was won by Heracles as a prize (although she eventually married his son, Hyllus). All names starting lo- are difficult, and for Iole we can only suggest a 'moon' allusion (as for lo) with perhaps the latter half of her name being a shortening of laos, 'people' (which in its Ionic form was leos).