Ai was sometimes recognized as Aoi mac Ollamain, the poet of the Tuatha de Danann. When Ai's mother was pregnant with him, the house was rocked by a great wind and a druid was said to have come and foretold that the child which was going to be born would be gifted with special powers. The king ordered for the child to be killed. But his father, Olloman, saved him from that fate. The child grew up and when he was older he asked a boon of the king. Consequently, from his poetical pleadings, he was given the name Ai which means "poem."

Resource

Ellis, Peter Berresford. A Dictionary of Irish Mythology. (Santa Barbara, California: ABC-CLIO, Inc., 1987). Pages 24.