A Banshee (“woman of the barrows”) is a female spirit in Irish mythology. Traditionally when a person died a woman would wail a lament at the funeral. These women are referred to as “keeners” and legend has it that for great Gaelic families the lament would be sung by a fairy woman; having foresight, she would sing it when a family member died, even if the person had died far away and news of their death had not yet come, so that the wailing of the banshee was the first warning the household had of the death. In later versions, the banshee might appear before the death and warn the family by wailing. When several banshees appeared at once, it indicated the death of someone great or holy. The tales sometimes recounted that the woman, though called a fairy, was a ghost, often of a specific murdered woman, or a mother who died in childbirth.
She is often described as wearing white or grey, usually with long, pale hair brushed with a silver comb. This comb detail is also related to the centuries-old traditional romantic Irish story that, if you ever see a comb lying on the ground in Ireland, you must never pick it up, or the banshee, having placed it there to lure unsuspecting humans, will spirit such gullible humans away.
In some parts of Leinster, she is referred to as the bean chaointe (keening woman) whose wail can be so piercing that it shatters glass. In Kerry her keen is experienced as a “low, pleasant singing”; in Tyrone in the north, as “the sound of two boards being struck together”; and, on Rathlin Island, as “a thin, screeching sound somewhere between the wail of a woman and the moan of an owl”. In Scottish folklore, a similar creature is known as the bean nighe or ban nigheachain (little washerwoman) or nigheag na h-àth (little washer at the ford) and is seen washing the bloodstained clothes or armour of those who are about to die. In Welsh folklore, she is called the Hag of the mist.