In Irish mythology Etain was one of Ailill's daughters, supposedly with Medb. When Midir fell in love with her rejecting Fuamnach, his first wife, and married Etain, Fuamnach got jealous and cast a series of spells on her. First Fuamnach turned Etain into a pool of water, then into a worm, and then into a fly. Fuamnach then created a wind that sent far the fly until it fell on some rocks near the sea, where remained for seven years. After all that time Aengus found the fly and wanted to bring it in the form of Etain to Midir, but Fuamnach created another wind, and the fly fell into a glass of wine, which was swallowed (together with the fly) by a pregnant woman, what make Etain possible to be reborn. Years went on and Etain married king Eochaidh, but Midir got aware and went to Tara, Eochaidh's capital, to bring his wife back home. After several happenings Midir and Etain escaped from Eochaidh's palace and went home, pursued by the king. Thanks to Midir's magical abilities Etain remained his wife and Eochaidh was fooled.
Other spelling: Edain.