definition from
Oxford Dictionary of English –

banshee /banˈʃiː , , ˈbanʃiː /
▸ noun (in Irish legend) a female spirit whose wailing warns of a death in a house:
the little girl dropped her ice cream and began to howl like a banshee
[as modifier] a horrible banshee wail.
– ORIGIN late 17th century : from Irish bean sídhe, from Old Irish ben síde ‘woman of the fairies’.