- Mythical hills of Irish and Scottish folklore, home of the sidhe race; fairyland, faerie. [From 1793]
- Alternative capitalization of sidhe.
1914, William Butler Yeats, Rosa alchemica:
- Their reign has never ceased, but only waned in power a little, for the Sidhe still pass in every wind, and dance and play at hurley, and fight their sudden battles in every hollow and on every hill; but they cannot build their temples again till there have been martyrdoms and victories, and perhaps even that long-foretold battle in the Valley of the Black Pig.
- 2001, Mercedes Lackey, Rosemary Edghill, Spirits White as Lightning, page not numbered,
- “‘Fun,’” Ria echoed. “You want to invite me to one of the Sidhe’s High Holy Days—me—and you think it'll be 'fun'?”