What is "aibell"

In Irish legend Aibell (sometimes Aoibheall (modern Irish spelling), also anglicised as Aeval) was the guardian spirit of the Dál gCais, the Dalcassians or Ó Bríen clan. She was the ruler of a sídhe in north Munster, and her dwelling place was Craig Liath, the grey rock, a hill overlooking the Shannon about two miles north of Killaloe. Aibell also had a lover (called Dubhlainn Ua Artigan) and a magic harp (of which it was said "[w]hoever heard its music did not live long afterwards").