Sindarin name of the Misty Mountains (Let/180), more literally “Line of Misty Peaks” (RC/11), a combination of hîth “mist” (SA/hîth) and aeglir “range of mountain peaks”.
Conceptual Development: In Lord of the Rings drafts from the 1940s, this name first appeared as N. Eredhithui, with Hithdilias written above it (TI/124).
Misty mountains; hîth (“mist, fog”) + aeg (S aegas “mountain peak”) + lîr (“range, row”)