Ilk. urch n. “goblin” (Category: Orc, Goblin)
A Doriathrin noun for “goblin” developed from primitive ᴹ✶orku, also attested in its plural form urchin (Ety/ÓROK). The change of [k] to [x] (“ch”) after the liquid [l] was a normal Ilkorin development, but the change of [o] to [u] is harder to explain, as noted by Helge Fauskanger (AL-Doriathrin/urch). In an earlier version of the entry Tolkien wrote Dor. orch (EtyAC/ÓROK), which is the expected form. The simplest explanation is that this form actually developed from a variant primitive form *✶urku. There is a similar issue with Dan. urc, so perhaps this variant was used by those Eldar who did not complete the journey to Valinor.
References ✧ Ety/ÓROK; EtyAC/ÓROK
|Dor. orchin||plural||✧ EtyAC/ÓROK|
|Dor. urchin||plural||✧ Ety/ÓROK|
|ᴹ✶órku > urch||[orku] > [orko] ? [urko] > [urxo] > [urx]||✧ Ety/ÓROK|