Definition of "eldritch"

So Maggie runs, the witches follow,Wi' mony an eldritch skriech and hollo.

1790, Robert Burns, Tam o' Shanter

Pearl, in utter scorn of her mother's attempt to quiet her, gave an eldritch scream, and then became silent.

1850, Nathaniel Hawthorne, chapter VII, in The Scarlet Letter

The large vessel's dark form was massive, eldritch, as it loomed off the Cushing's port bow in the flash-lit darkness. This was the Hiei. The recognition of the battleship spread down the van, from the Cushing to the Laffey to the Sterett to the O'Bannon.

2011, James D. Hornfischer, “28: Into the Light”, in Neptune's Inferno: The U.S. Navy at Guadalcanal‎, New York: Bantam Books, retrieved 23 November 2022, page 276