topon. Hollin, (lit.) Holly-region
The realm of the Noldor in Middle Earth during the Second Age, translated “Hollin” (LotR/305) but more accurately “Holly-region” (RC/772). This name is a combination of ereg “holly” and the suffix -ion² “-region” (SA/ereg; PE17/37, 42).
Conceptual Development: In Lord of the Rings drafts from the 1940s, this region was first named N. Nan-eregdos in a chronology for Chapter XV (TI/166), but appeared in the draft text as N. Eregion (TI/124-5). This form also appeared in the Etymologies, already with the derivation given above (Ety/ÉREK).
A forested region within Doriath (S/121). The name resembles Eregion, and probably has a similar meaning. Christopher Tolkien indicated its initial element is a variant form of ereg “holly” (SA/ereg), and its final element may be -ion² “-region” (as suggested by David Salo, GS/389).
Conceptual Development: In Silmarillion drafts from the 1930s, this region was first named Ilk. Region (LR/126), which was designated a Doriathrin [Ilkorin] name in the Etymologies, the genitive plural of Ilk. reg (Ety/ÉREK).