A verb in The Etymologies of the 1930s glossed “to rend” derived from the root ᴹ√NARAK “tear, rend (tr. and intr.)” (Ety/NÁRAK; EtyAC/NÁRAK). In The Etymologies as published in The Lost Road Christopher Tolkien gave the form as narki (LR/375), but Carl Hostetter and Patrick Wynne corrected this to narka in their Addenda and Corrigenda to the Etymologies (VT45/37).
Qenya
rista
noun. cut
rista-
verb. to cut
narka-
verb. to rend
A noun for “a cut” in The Etymologies of the 1930s under the root ᴹ√RIS “slash, rip” (Ety/RIS). It was also an element the name ᴹQ. Latimberista, Quenya equivalent of S. Imladris, in a page of rejected notes from 1948 (PE22/127). It might reappear in some later notes as well; see Q. rista- “to cut” for further discussion.