Wilderness east of the river Gwathló mentioned in The Lord of the Rings appendices (LotR/1089) and appearing on its map. This name is translated “Central Wilderness” (PM/328) or “middle-people/region” (Let/224), a combination of ened(h) “middle” and the lenited form of gwaith “people, region” (SA/gwaith, Let/224).
Conceptual Development: In Lord of the Rings drafts from the 1940s, this name first appeared as N. Enedwaith “Middlemarch” (TI/296). Elsewhere, the Noldorin word for “middle” was given as N. enedh < ᴹ√ENED (Ety/ÉNED). Tolkien may have used a d instead of a dh because he did not want to confuse his readers with this unusual combination of letters. There are other examples of this in the Lord of the Rings drafts, such as N. Caradras for S. Caradhras, N. Caras Galadon for S. Caras Galadhon, N. Fanuidol for S. Fanuidhol, N. Galadrim for S. Galadhrim.
Some examples of d >> dh were corrected in published version of The Lord of the Rings (Fanuidhol, Caradhras), others not until the 2nd edition (Caras Galadhon, Galadhrim), but Enedwaith has never changed in the published text during Tolkien’s lifetime. Nevertheless, in private notes Tolkien sometimes wrote Enedhwaith (PM/328, VT42/7, NM/379) and in one place even stated that Enedhwaith was misspelt on the maps of The Lord of the Rings (VT42/20).
In later writings, Tolkien vacillated between ened and enedh as the proper Sindarin word for “middle” (for example, VT41/16 vs VT48/25). It appears he was unsure how to address the issue presented by this name, whether the name itself was incorrect or whether he should revise the Elvish words for “middle”.
enedh (“middle, center”) + gwaith (“people, folk, region”)