sidhe noun alsoshee\ˈshē\ (pluralsidheorsidhes) Etymology: partly from Irish sīdh fairy hill; partly from Irish sidhe fairy folk 1.plural sidhes: an underground fort or palace in which fairies in Gaelic folklore are held to live 2. a.sidhe plural: the fairy folk of Ireland in Gaelic folklore b.: a member of the sidhe : a fairy in Gaelic folklore — compare banshee